Price Lock terms completely ignored by MultiChoice.

I am on a Price Lock with DStv which I understand to mean that, contractually, my monthly subscription is set for a period of 24 months. I still have 4 months of Price Lock left. No problem for DStv - Price Lock or not, they decided to increase my debit order this month. When I queried this with them, I received the following response via email: “The system has currently removed the premium on price lock and is charging the new price for 929.00 and 120.00. Please note we will escalate to reduce the subscription as is (sic) still has 4 month’s remaining.” Oh my word!!! While I am keen to cancel my subscription, I am not able to right now because I am contractually bound to Price Lock. However, MultiChoice has no problem with breaking the terms of our contractual agreement. Why is it called ‘Price Lock’ when they don’t even stick to their own terms to lock the price? I wonder how many Price Lock customers have not noticed the increase in their debit orders …..