MBD credit solutions harassing me for non existing debt

I have been receiving phone calls from this company claiming i am in arrears with my truworths clothing account and demanding payments..i haven't had any accounts for the last 15 years so how is that possible for me to be in arrears of an account that does not even exist.. I also phoned truworths gave them all my details and the consultant rep**** saying " Sorry Mr van dyk but there is nothing on our system and no account information which means that you do not have an account with us"....So then i phoned MBD CREDIT SOLUTIONS and spoke to a call agent Moses (Which i can say was atleast very helpful) after giving him all my details and asked him if he could please just check on their system what is going on and why are they contacting me for debt after 15 years..Moses then said but sorry Sir nothing the details that u gave me comes up on our system...So now i am asking,, if truworths has nothing on the system and according to the MBD call agent moses i also dont exist on their system WHY DOES MBD CREDIT SOLUTIONS KEEP CONTACTING ME..so lets just say i did make a payment can anyone tell me where or to who the hell would my money then have gone to.because i dont exist on truworths data base neither do i exist on MBD data base