Debt Collectors Harassments

I had taken out a loan with Electric Express some years around 7 years id say in which i was paying every month until the company had liquidated i had not been contacted or received any form of communication in which to say that there was another company that took over or to where i now needed to pay the outstanding balance of R2000. Its been years and i now receive a call from a DMC consultant demanding i pay them R10 000 for this account. They had sent their consultants to my previous residence claiming to see me with no ID documentation of who they where they where given my cell number and asked to contact me as i no longer live there, upon this i had a female consultant watsapp me and harass me on whatspp.

With all due respect i do not think i am liable for the outstanding balance of this loan as i was not made aware of the company closing down nor was i asked to pay the outstanding amount to any other company.

Please can this be sorted out as this debt was supposed to be null and void due to it being over 5 years you guys cannot be claiming from me now this was supposed to wiped out as of the new law.