Should the print company I use be able to change a file to spot color for me?

Question

I recently sent a document in to a major print company to have a folder printed.  The document was created in Illustrator using only two colors. They said they could not print it because it was still more than two colors and that I needed to change it to a two color document using Pantone Spot Color.
I've never had to do that for a print company before but I've also never had a two color project before. I opened the file back up and selected my objects and "recolored" the work and deleted all the swatches aside from the two colors I needed that were now Pantone Spot Color (HSB). It literally took me 2 minutes.
The reason I am asking is because they pretty much said that I don't know what I'm doing, which to a designer is completely insulting.  We all do new things from time to time but that is an insult. Shouldn't they, a large print company with years of experience, know how to do this for me? They had the original design file.. Maybe they don't know what they are doing?
Any clarity on as to why I needed to do it and not them is greatly appreciated.  Also.. any direction as the best way to use spot color over cmyk is appreciated too.

Answer 1

...which to a designer is completely insulting...
What's so special about "a designer"?
Prior to the mid 1980s, designers could get away with prima Donna attitudes, because they (or their employers) were paying pre-press "color houses" around $350 per hour to tweak colors to sooth their oh-so-erudite discernment and hyper-developed color sensitivities, and to gain reimbursement for the $100 per plate lunches on proof-check days.
That all changed when designers (and their employers) got tired of paying those fees and took on the responsibility for the technical side of assembling their designs into something printable. That was the so-called "desktop revolution" and "revolution" was not a bad word for it. It turned a huge industry on its head. Color houses which didn't adopt PostScript devices and workflows were soon dropping like flies--and so were designers who didn't climb down off their lofty pedestals and buckle down to learning the technical realities of what they were doing.
Don't be insulted, but the simple fact is, you still don't know what you're doing if you think converting any given process color job to a two-spot job is "just a couple of minutes' work." Only in the very simplest designs would it be as simple as re-defining a couple of process Swatches as spot color Swatches.
In Illustrator in particular, doing so won't even work if the original Swatches were not originally defined as Global Swatches.
If those two process Swatches were used in any Blends, converting them to spot will likely not update the intermediate steps of the Blend. In earlier versions of Illustrator, the same problem applied to grads.
You can often get away with not having properly trapped the file with process swatches, because there are potentially four component inks which may be shared between adjacent different-color objects. Spot inks are not so forgiving. Trapping is essential if the two spot colors touch.
So you really expect a printer to just have a policy to do that for you? And thereby bear responsibility for anything they may misinterpret or overlook that may cause a registration sliver on press and thereby loose every bit of profit on the printing (which these days is cut-throat competitive)?
No. It's your responsibility to build the file correctly. The printing houses I use know better. They know I would have a coniption fit if I ever caught them modifying one of my files. They know they are to return any problem file to me for correction.
JET