Need help with MCM

My husband just got a letter in the mail from MCM saying that he owed around $2,800. He had no clue what this was so he called the company and a very rude guy who didn't speak English well started firing things out at him that he had a credit card that he stopped paying on back in 2002 and the balance was transferred to MCM. He said that we could pay $1000 right that second over the phone or else we had to pay the whole thing. This is the first notice that my husband has gotten about this credit card since 2002 when he thought he paid it off and we have been living at this address for 5 years. I then got on the phone and asked the guy to send me a letter validating the debt which he pretty much refused to do because he said he already sent us a letter--which has no details at all. I also told him I was going to tape record the call and he told me he didn't authorize me to do that and then hung up on me. We checked my husband's credit report and there is NOTHING on it about this debt at all. I looked up the statue of limitations in our state and it is three years, so even if this debt is legitmiate, it is way past that. I need to know what should I do at this point? How can this debt be real if its not even on his credit report? Someone please help...