TELKOM FAULTY, OVERCHARGED AND INCONSISTENT BILLING

I had a 24 months modem + data contract with Telkom with a R100 monthly subscription payable through a debit order. Telkom has never billed me this amount as agreed instead the FAULTY deduction will go through after 3 (three) months deducting more than what I was suppose to pay; the highest being more than R1000.00. Their billing are overcharged and inconsistent; does not even match with their monthly statement which are mostly received after two-three months. I have cancelled their contract many times through their customer service centre and I even went to their branch to lodge a complaint but my case was not resolved no matter the messages they send me that this matter is resolved but the deductions went through having to pay more than R2000.00. I went to my bank to reserve this amount and cancellation of a debit order but they keep on changing the reference number for the deductions to go through and so far this case has affected my credit profile very badly.