Poor service and do not want to pay back money they debited incorrectly

Hi the service received from Telkom Is really poor I have been contacting them for over a month now because they had suspended my account advised I do payment I did go through and pay at store then they had also debited my account now it’s going over a month they have not reversed my R2600 on my second last conversation via email consultant had advised documents received now I called to find out it’s been 2 weeks I’m still awaiting my money they tell me they haven’t received documents plus on the 15 th of June I received an sms my case is resolved I’m really tired of calling them if anyone can advise how I can take this further I have all emails and calls