Very Poor Service

I took out a contract with Mondo on 2017-11-29. I received the simcards on 2017-12-01. On 2017-12-03 (in the cooling down period) I send 5 e mails to Mondo requesting the cancellation of the contract. I also tried to phone them on their no but not once was the phone answered. The cards were never activated. Today I found that an amount of R 353.74 was deducted as "Telkom Mobi" from my bank account. I did not want the service and did everything possible to cancel it. What do I need to do further, except for consulting with an attourney. I will never ever in my life make use of such a pathetic service again.