From Isb-Pindi Bhattian, when I left motorway, the guy collected Rs. 300 and didn't give me any reciept (i left after few seconds, anticipating a receipt and not getting one).
On my way back, at Isb exit, they got Rs. 300 and gave the receipt. The card itself had no damage.
I suspect some of them may be involved in getting money under the table. But in my case, Rs. 300 was charged in both cases, so chances of fraud are low.