I finished the 24 months contracts but I still get billed for that

Vodacom is causing headache for me. I finished paying all my 24months contracts but Vodacom is still invoicing me putting my name in arrears and ruining my credit score. I have sent this to my lawyers and Consumer Protection Ombudsman and I want to cancel any business doing with Vodacom after 11 years relationship with them this what I get.