Telkom Unauthorized spend limit and charges

Telkom debited me 2.2k for a contract which i pay R548 each month for. When i logged into my account i seen that spendnlimit of R1500 was loaded onto my account which was not authorized by myself. Check emails and sms messages and no notification of this change was sent to me. I have tried multiple time over the past 3 days to contact Telkom with not luck as their IVR just loops you and never connects to an agent. I requested a callback and they call and drop the line. I need this problem fixed and my refund