Left the country, terminated my contract and still being billed

I had 2 contracts (cellphone ********** 479 and WiFi) with Cell C. I left South Africa to work in Canada in Feb 2017 and timeously terminated both contracts. The WiFi contract of R99 has been charged monthly to my debit account despite emails to ********** to terminate this account. This monthly billing has cost me R1200 to date. A family member in Cape Town, who has power of attorney over my accounts, has gone into the Cell C store to relay these messages with no effect. I want the account terminated and my money refunded.