MTN - BEWARE OF THEM

I had an MTN contract that had come to an end. In approx 2020 I went into an MTN at the Mall of the South and requested the contract be cancelled as I do not utilise the contract. They advised at the time one months premiums would be taken off following which the billing with MTN would stop. I app**** a year and a half later for a business loan only to find out I was black listed by MTN for an amount of approximately R4500.00. I tried calling various numbers on the internet to get hold of MTN to no avail. I have not received a single correspondence or call from MTN since I cancelled the contract in store. 2 days ago I received a call from lawyers advising I now owe R11 000.00 on the account. BEWARE OF MTN - as mentioned in 2 years I have not received a single call from them advising outstanding monies. Now the onus is on me to prove innocence.