Unlock code from provider didn't work

I was with Suncom when I got my 580i in Nov 2007. Sept 2008 Suncom went T-Mobile and instead of keeping my suncom sim I stupidly replaced with a t-mobile sim even though I didn't have to. Well they got me the unlock code for my husbands nokia and worked no problem, but no joy with the 580. Customer service said they had the IMEI wrong and sent me another unlock code. It was the same code. Needless to say I have tried the unlock code about 50 times because I am blonde. Sony says because I tried more than 5 times nothing will work, but I refuse to believe them. Now when I did *#06# the IMEI code on my phone is 17 letters, but take the battery out and the IMEI code is 15. The 15 is the code I recieved the unlock for. Haven't called to find out if it would make a difference because I remember them telling me the IMEI was a 15 digit number. I have read also on my google serches that I need to ask for the subsidiary unlock not PUK and I don't know what the heck the difference is. Before I start trying to upgrade firmware and or removing sim lock - Am I screwed because of blonde moment unlock code overkill or should I call CS and find out if they got me PUK not subsidiary? Or they really did have IMEI code wrong because they missed 2 digits?:confused: