Bull**** service provider

MTN is a bull**** service provider!! I thought moving my contract from CELL C to MTN would be better but I guess not!! I signed a contract with them for 24 months and ended this, they still decided to debit me after that and I reversed the debit order, after doing that they handed me over to their legal department!! After asking why when I called, they said due to non payment and that I needed to cancel the contract! What bull**** is that? I have my contact stating my contact is for 12 months!! I have proof stating ALL 24 payments have been paid!! I'm highly ****ed off!