Was promised 12 washes, got 2

The product works well, but the amount of washes per can is absolutely incorrect. I was promised 12 washes per can. I washed a C-class and a Nissan Micra. After these two washes the can was dead empty. I contacted the customer services regarding the matter. The reply I got from them was nonchalant. The representative told me that the can will only last four to five washes and the person did not seem to care at all. No apology, nothing.<br> <br> Well, that is disappointing. By the salesman I was promised 12 washes, customer services said four to five, and I got two...