DSTV incorrect billing

I won a reward which we were eligible to claim from 15 December to 15 January. The reward was 1 month free Premium subscription. We claimed the reward and it automatically kicked in on the 27th of December. On 5th January, I noted that my monthly subscription had changed to R818, which is the monthly subscription for Premium. I queried this with DSTV. I was told not to worry that I would be billed for my normal Compact Plus subscription which is R600. On the 27th of January, R818 was debited from my account. I sent DSTV an email. I called and was told the incident would be escalated. I have not received any feedback from them.