Podcast Image is Not Updating for over Two Weeks

Question

Hi. I use Wordpress - > Feedburner - > iTunes Store and my designated podcast image has not been updated in the Store for over two weeks. However I will note that on the Apple Podcast App, and in the iTunes Podcasting Section in my iTunes Library, the image updated almost immediately. It's only in the store that it's a problem, plus, that is the URL we use to share on Social Media. So it's code red!
I have been following all the threads, and understand that sometimes the store gets "stuck," but we are reaching hair-pulling-out-of-our-skulls mode, considering our large audience-base and the regularity with which we share the podcast on Social Media.
The outdated image, which iTunes Store is still displaying, does not exist anywhere on or offline at all. It is behaving as a ghost, not the scary kind the really f*cking annoying kind. I have no idea how in the world the store is still accessing it. It is 2014, and I simply cannot believe that Apple Technology would be this sluggish, and so I'm beginning to suspect I've messed something up somewhere, and really I'm at a loss and I can't keep telling my superiors that it's someone else's fault and HELP HELP HELP
anyway (clears throat)
Here is the wordpress RSS:  http://stephenmansfield.tv/category/podcast/feed/
Here is the Feedburner RSS: http://feeds.feedburner.com/MansfieldPodcast
Here is the correct media URL I entered in "SmartCast -> Podcast Image Location" on Feedburner over two weeks ago:
http://stephenmansfield.tv/wp-content/uploads/smp-icon-2013-1400x1400.jpg
Here is our iTunes Podcast URL which is magically (read stupidly) displaying a non-existent jpg file as our image:
https://itunes.apple.com/us/podcast/stephen-mansfield-podcast/id433416409?mt=2
BLARGH!! Thanks!!
isaacdarnall.com
idintify media
ebooks | podcasting | music | photos

Answer 1

After over 8 weeks, I got my image updated. I don't know exactly what did it. First I followed Roger's advice and changing the file name to a name that had never been used before. The fact that I reset back to an earlier image, thus a file name that had already been used, maybe confused it a little bit. So I changed the file name and re-uploaded. I also compressed the file size down a notch to make it smaller.
Finally, I bugged Apple tech support on the phone to no end (sorry sir, we don't know how to fix this, sorry sir, we don't really understand podcasting) until they gave me this email adress, and there, they told me they reset the feed:
Podcasts at apple .com
It is 2014, and updating a dedicated Podcast image should not be this hard. They need to totally revamp their system. I think the more we complain about this on the forums, the quicker this will happen.
This is the only podcast directory that has this outdated problem. Unfortunately, it's also the most important podcast directory.
Apple Fail.