Debit Orders

I received a call from Roving jet offering me a shopping voucher, which I refused. The following day they called again asking I received an sms, I said no and asked me to confirm my number so that they can send an sms explain how it works. Then 2days later I got debitted R99, tried to reverse with the bank then they debited another R99 with a different reference. I tried calling them but I can not go through. We did not agree on this and I didnt even get thd sms.