No customer service

I have been on vodacom pre-paid for almost one and half years after deciding not to renew my contract. I was surprised to receive a final letter of demand from Vodacom indicating my "account" has been taken to legal. I have since recived appalling service in trying to resolve this. Everytime i call the legal number i get routed to "customer care (what a joke of a department) because my number does not register as owing on the vodacom system. The few times i have been successfully transferred to collections department, i have received the same promise of "we will send you a letter" confirming account is not in arrears, but this letter never comes. I have made so many calls to vodacom to try and resolve this that my number is currently blocked from contacting vodacom. In all my efforts i would be very ****ed if i end up being blacklisted for an account i do not owe. The level of service i have since received from vodacom is appalling to say the least.. and yet everyday they spam me with covid messages instead of resolving my problem.