POOR SERVICE

There is someone who took out a contract package with MTN last year 2019, I have contacted MTN and nothing was done, now Iam affected by this whole thing with my credit record. Iam not happy about this, because I have done all I can to report this to MTN, that I know nothing of the account and they should close it, The account is active, and the person is utilising the services as seen from my credit record. Dispite my attempts to have them close the account, nothing was done. This is affecting my credit viability as many payments have been missed, and I cant do anything about it. Can someone help me in this regard. MTN is really frustrating me.