Getting penalized for spending "too much" with Engen

I got penalized for spending "too much" at Engen. I tried to accumulate points with a Clicks Club card and went out of my way to fill up @ Engen. I didn't receive the points and after a huge effort of proving that I filled up @ Engen, swiped a card that is not a fleet card, swiping the club card, I was contacted and said one of my purchases was over R3500 and therefor they had to put a stop to my card and my points. They send me a mail asking me to explain why I was buying so much and if I have an account with a service station. I could not believe what I was reading. Instead of rewarding a loyal customer, they were penalizing me and querying why I was buying such a lot. I paid for that fuel, I did not ***** it. I supported them, not damaging anything of theirs and they are unhappy about it. They say that on the t's & c's is states that you are not allowed to buy more than R3500 at a time. Is this not the most radicicolous thing you've ever heard? There are so many of my friends that are getting rewarded for filling up with Engen's opposition and their partners. Don't know why I wasted so much time and effort trying to support them. The owner of the specific service station thought I was joking when I contacted him and told him I got penalized for filling up too much. The very rude lady from Engen had the edacity to ask me if I now want my points or not. I'm sorry, but I still can't believe this!!!!!!