DSTV Price Lock contract overcharge!

I have a "Priice Lock" Premium contract with DSTV and was incorrectly debited with R1145.26 on 31 August instead of the correct amount of R994.00. I took this up with their call centre & on 5 September was contacted by email by Katleho who promised to fix the issue. I asked whether the next debit order would be reduced by R151.26 being the amount overcharded or if I would be refunded this a,ount and was told that this had been "escalated". On 12 September I again queried this with Ndivhuwo at the call centre but was given the same answer. Despite 3 subsequent emails requesting an answer, I have not had a response. The overcharged amount is relatively small but DSTV are in breech of the Price Lock contract and I want this fixed!