Harrassment by CreditIntel

My mom is a 82 year pensioner and she never had a loan with Smater Finance, yet she keeps on getting messages and phone callls as follows.

"Why do you refuse to pay your debt? R13515.87 owed to Smarter Finance. FNB Ac *** Br: 250655 *** CreditIntel Tel ***" - this message was send to her yesterday again.

Even after contacting CreditIntel, they still keep on harrassing her. I get no replies on my e-mails or proof that it is her signature on the loan documents.