OVER BILLING ON HYBRID CONTRACT

Hello Peter , I'd like to log a billing complaint on my Vodacom internet account , I was offered an additional Internet account by a call centre consultant.The contract was suppose to offer me 2Gigs at R99.00 on Hybrid and once the 2Gig cap is reached , I was to top up as per any other Hybrid contract.I've had the internet Hybrid contract for 6 months without problems(at R99.00 p/m as agreed) , then at the end of March a R 11346.00 deduction was made on my account , instead of the normal R1100.00 monthly deduction (since I've other two vodacom Hybrid contracts at R500.00 each).I've tried to get vodacom to rectify this but , I've since gotten no assistance from them and I need the R10246.,00 overcharged on my account reversed.My first contact with them was on the 02 April 2015 Ref:S3-82U5X-XJXJ and they've since not responded to my other numerous attempts to get help.