Very suspicious ******

My car went for service in July after I bought a R500 Wikideal voucher. They deceive people to fall for their trap and charge you a lot of money after all. I had to pay over R4000 for service. What passed me off is that, they took out the coolant in my car and put water. The coolant tank it's now have rust and probably my engine. I hate these suspicious ******. Don't take your car to them.