Unkowledgable about the law.

As debt attorneys(or so they claim), they should be knowledgeable about the "lapse" clause. So - I have a written confirmation in my possession that my account with a pathology service provider is standing at ZERO. Yet these fools keep trying to convince me that I have outstanding account from long long long long (did I mention LONG) ago. By this time anything that far ago has already lapsed, meaning throw away and forget about it. Yet, sms upon sms... Man, no idea where these guys got their qualifications.