Cannot download my 15 available downloads, error says store is temp unavail

Question

I reported the problem through iTunes around 12/5 and they replied once about 8 days ago with a standard boiler plate reply, telling me to do several things that I had already done. I wrote back with more details and got no reply, and then I wrote back a couple more times - but it's almost like Apple is ignoring me now. Even when I opened a new trouble ticket last week by reporting the problem with a different purchase they have not replied in three days. That is not acceptable.
There is no error code number. When I try to check for available downloads I get the error message "Unable to check for available downloads. The iTunes Store is temporarily unavailable. Please try again later." There is no problem with my Comcast cable internet.
The problem started on Saturday 12/5/09 when I bought "Saturday Night Live with Zac Efron" on the Apple TV to watch with my kids. and neither the Apple TV nor my 2 Macs would download without the above error. When I tried to download 11 iphone apps updates on my Macbook Pro later that same day, I got the same error and everything was added to my "Available Downloads" queue for downloading later (the TV show and the 11 app updates). Now 8 days later I am up to 15 available downloads that I cannot get.
I am using Comcast cable internet and have had no disruptions, and it is downloading everything else at 7+ mbps with no problems. I can browse the iTunes Store, listen to previews, and occasionally I can even buy something new and it will often download fine. Prior to Dec 5th can't recall the last time a download from iTunes has failed. Since the 5th, IF the download fails then my "available downloads" queue gets bigger and bigger as the failed download is added to the queue. Any time I go to Itunes > Store > Check for available downloads I get the same message quoted above.
Somehow on Sunday the 6th I was able to download that one Zac Efron TV episode on the Apple TV (the purchase that started it all). I was also able to purchase a new album on my iMac Sunday and that downloaded fine. But when I did an iTunes Plus Upgrade of "Enya A Life in Music" with my iMac on Sunday it failed to download, and it was added to the download queue which wont download and I still can't get it.
In problem solving, I even added my iTunes account to my account on my son's Macbook and authorized it, and it was not able to download any of the "available downloads" by using "Check for Available Downloads". I also checked permissions of the itunes data folder and did the terminal command to change permissions that the apple support site suggested (even though permissions were fine). I even created a new iTunes folder on a new hard disk formatted for Mac, and had iTunes copy everything to the new hard drive (using the APPLE instructions for creating a new iTunes folder via iTunes preferences). I did that because my original iTunes folder was on an external MS DOS FAT format disk, even though that drive has been working fine for 3 years. I have done ALL of the trouble shooting tips that the Apple support site recommended.
Because the problem exists on a fresh macbook and after the trouble shooting, I believe the problem is with my account at iTunes, and I think that I need to have the "available downloads queue" reset to zero, and then have the Enya iTunes Plus upgrade added back in. I have no way to get Apple to do that or anything else for me, despite having spent hundreds of dollars, if not thousands on music, movies and TV Shows. I am baffled by their lack of response to my "Report a Problem".
I don't know what to do. I am now worried that every time I purchase something new, that if it doesn't download that I will never get it. I have some application updates that I can't download because iTunes tells me I "have already purchased this application but have not downloaded it yet." I have too much invested in my library to just go away. Can anyone please help!
(An added note - For many months or even years my iTunes account has always shown that I have 1 available download when I have none, but it has never failed to download purchases that are waiting for me. For instance if I had Greys Anatomy TV Show subscription ready to download the number of available downloads would say "2", and the TV show would download fine and the number of available downloads would drop to "1" again. Thus, I suspect there is a problem with my iTunes account, and not my computers or ATV. I reported this once to Apple and they did nothing about it, and I ignored it since it has never caused a problem.)

Answer 1

This is bad - I have an Apple automated response that they got my report on 12/6, 12/10 and 12/14, and I haven't heard anything from them since the 6th when I got one reply that told me to do things I tried before reporting the problem. Between the 6th and 10th I replied to their response 4 times and they ignored me, forcing me to report a problem with two more items that wont download but getting no response.
How do they get away with this kind of behavior, especially for someone with FIVE Core 2 Duo macs and thousands of dollars of of iTunes store purchases? I'm getting really ******.