Bad Customer service

I booked a coupon for service from Wikideals. i took my car for service today and they told me that i need to change brakes and they charged R1500. now when i have to collect the car they told me they dont have a speed point i must bring cash. I cant withdraw cash from credit card also i cant make pay and clear now. If they told me before that there are challenges with payments i wouldn't have given them a go ahead to fix the brakes. Now they want to keep my car because they want cash or pay nad clear now ofwhich i cant do those things. Bad service, i will never take my car to them nor recommend anyone for that matter.