Mercedes SA don't care

I recently complained to Mercedes SA about having to pay more for oil as the dealer only had 500ml containers and no 5 litres. The response I received was that I could go to a dealership in Johannesburg that had stock. Not quite the response one would expect if one lives in Pretoria. They seem to have an attitude that as an owner you must accept what they offer and not question anything they offer. Disgusting, considering what one pays for their vehicles.