Sold me wifi contract with wrong information

I had Mondo Customer Support phoning me to sell me the wifi package on my cell phone contract. The conversation was recorded. I have reported a complaint to them stating that i need to listed to the recording. Since February I battled to get the recording from them which was retrieved last week only. I gave them 5 working days to cancel the contract because it states clearly in the recording that I did not want to pay anything extra for the above, which I then did get a bill for R99 a month. They did not do anything about it till today