how do I still owe to Video Computer Store

Back in 1999 when I was watching tv I saw an infomercial for Video Computer Store for a new PC. I called the number and was approved and the PC was sent and received later.. (I guess I was one of the lucky ones, we got the whole system, some did not). It was on assumption that this was an installment contract with MBNA who was contracted to finance the PC's with a 3 month deferred payment and several rebates which we got all we could and all were honored. The pc package was worth around $1,500 at the time and the payments were to be around $52-$80 but after all was done.. it came out to be $92.. not sure why. I paid faithfully until Sept. 11th, 2001.. when work suddenly came to almost a full stop..so I asked MBNA for an extention on the loan which is not uncommon for installment loans. I was denied because MBNA said they could not do it..nonetheless.. I couldn't make the payment.. but had made every other one since then until several months ago after we found out that our loan wasn't an installment loan (at least that's what MBNA said) and also after we did the math and found out we paid about 4 times what the pc was worth a few months ago and decided to not make any more payments.. MBNA said they were to charge it off..which my credit had already suffered over the last 3 years anyway because they didn't allow me the extention that one time (installment or revolving?) my credit has suffered because each month it showed me 30 days past due even though I made them religously for every payment after the one I needed the extention for but they did not allow. I work long days so my wife got all the phone calls and found that a new collector was trying to contact me on behalf or sold to from MBNA.. and they were very rude, even threatening garnishment.. but no written communicato for months..after about 2 months of them I told them to send me something because they never sent anything written..even though they adamantly claimed they had..nothing, just phone calls, so I suggested they send something by registered mail (still nothing registered).. all from the same company. sometimes they got ahold of me and kept asking if I refuse to pay this "debt?", I always said no.. I am more than willing to pay a debt that I feel that I owe and also told them that I dispute the debt. ( I have paid close to $4,700 for this thing). Have finally gotten written correspondence from this company on Saturday, August 6th, 2005.. but through a different person and seems quite placid in nature except for the collection itself..which you already know I don't feel that I owe anymore. I am not sure what to do and don't know who to go to since if I could afford an attorney.. then apparently, i could afford to pay the amount that they are trying to squeeze from me. P.S. I also found that the company I bought this PC from had mislead MBNA too but also found that MBNA was contracted to provide "installment" contracts to those of us who decided to purchase full financing instead of using a check or credit card and was involved in a class action suit through the Attorney General of Pennsylvania at that time against the VCS (Video Computer Store) also d.b.a. as Computer Personalities or something to that effect. Not sure what to do..am at long end of a short rope. thanks for any help in advance.. Sincerely, Dale