Poor Customer Service

Firstly I have been over billed for a top up line which does not make sense. I have contacted the customer care line and no one has called me regarding my account. My line has been barred with no explanation. I logged a billing enquiry and I was advised I will be contacted back and up till this day I have not been called. I have used all social media methods to get you guys to contact me since you are unable to assist me over the phone but there is still no service. I went to the store and requested for banking details to be changed but you guys are still debiting my old bank. Such pathetic service from you guys. I want my account cancelled as I have been trying to get my query resolved for over 2 months.