Complaint of cancelation of mobile contract

I took out a contract online, was told I had a 7 day cooling off in which to cancel the contract this was on the 17 May. Received the phone on 27 May and my bank account was debted for the installment. Called the customer services number on the 24 May to cancel the contract. Spoke to the guy (Byron) from the online sales dept as he assisted me with the application and he advised that he would send an email for the refund. Till today I have not heard from him again. Called the sales dept, customer services and the billings dept till the Friday and was sent from pillar to post without any success. Then the Friday I called customer service and was told that I must cancel the contract online which I did and received a case number. Call customer service again and was told I can't speak to a manager as they will not be able to assist with this problem. I called the mutual park branch spoke to Jason and explained the situation and he checked the system and told me that telkom is waiting for me to tell them where they must fetch the phone, which no know one contacted me about. Jason said I could bring it to the branch and they would put a note on the system, which they did when I took the phone to him and left it there. Then 07 June I received an invoice for double the amount to be deducted from my account on the 25th. I called customer service and spoke to Siyabonga Moloi who advised that he would send his manager an email explaining the issue and request that he call me back. Till today no one has called me back.