Mondo exploits pensioners

An agent phoned my pensioner father of 78 years to offer an additional MTN contract at R99pm for 36 months. My father never agreed to the contract, yet a sim card was delivered. It has never been activated, and he and my 77 year old mother have been visiting MTN stores IN PERSON during COVID to try and cancel this contract, with NO SUCCESS. Now that my father's actual contract expired, he cannot even get a renewal until Mondo gets paid R500 for the past 5 months fees although they never accepted the offer nor activated the sim card. My old father has driven around and spend and paid for hours of calls on his Telkom line to get it resolved. If there is ANYBODY from Mondos who can please get this contract cancelled and reversed, please contact me urgently. As I do not know Mondo and I ONLY ever deal with Vodacom. I need to get someone to stop this Exploitation of innocent pensioners!