Red Hawk Spur gives the finger to customers

I've been a regular at this Spur for years, until tonight that is. Apparently they've changed management, and the new manager couldn't care less about their regular customers. After a minor dispute regarding my usual order, they called the new manager, who didn't even try in the least to be accommodating - in fact, he simply told me "No, we don't do substitutions any more". So I told him in that case, he can just cancel my order and bring me the bill for my drink, to which he simply said "Sure.", without even attempting to discuss this further and reach a mutually acceptable solution. He has now lost them a long-standing regular customer, and all this over what's the equivalent of about R10!