I boarded a bus and inserted my pay-card into the pay machine to pay a fare of 11.00 Shekels. The driver accidentally pressed the wrong button and the machine charged me only 5.70 shekels. When I pointed this out to the driver, he said that he could not cancel the payment since someone else had already made a payment with his card in the interim, and only the most recent payment could be voided. Since I had only paid 5.70 NIS I still owed 5.30 NIS to complete the 11.00 Nis fare for my ride. The machine did not have an option of processing a payment of 5.30, only either 8.00 or 5.70 NIS. Someone suggested that I pay another fare of 5.70 which would bring my payment sum to a total of 11.40 Nis which would cover my fare.
Since I had not paid the full fare amount at the beginning of my ride, and about half the trip time had already elapsed since the first payment, The remaining 5.30 Nis which I still hadn’t paid was now a debt. So my question is: Would I be allowed to pay another fare of 5.70 NIS while my debt is only 5.30 NIS?
Would it have made a difference if I had added the extra 5.70 before exiting the bus, or may I still pay the extra 5.70 even though I already left the bus, and now the 5.30 owed is definitely a debt?
Note: If I pay another 5.70 I have no intention of going through the whole bureaucracy of getting reimbursed by the bus company.
There is no issue of ribbis here because the reason you are paying them extra is not because you took a loan from them, but because you want to make sure that you paid the full fare, and you don’t have any other way to do it. However you don’t have to necessarily pay a fare of 5.70, you can take a local ride, which might cost you only 2.30 or 3 nis, which will cost you less.
There is rumor in Eretz Yisroel, that the payment for busses is made to the Ministry of Transportation, and their rule is that if the bus company didn’t give you a way to pay, i.e. the machine wasn’t working, that you don’t have to pay. In your case, if the driver is the one who made the mistake and they are not giving you a way to pay the rest, it is possible that technically you might not have to pay nevertheless the correct thing to do is to compensate the company for the remainder of the fair.
Conversation with R’ Y. Cahen shlit”a