Sainsbury Petrol Station Aylesbury review: Forecourt staff

Tuesday 14th April at approximately 09.30.
I visited the above petrol station to top up my car, Using the pay at pump facility. I proceeded to fill my but before it was full i noticed the fuel had stopped but the cash counter was still ticking up further costs. I obviously went into the cashier and explained what happened. They were not interested in helping but suggested I contacted trading standards. I am disgusted by their attitude. I went back to my car and was approached by a have driver who was waiting to use the pump. I explained what had happened to me, and he explained that the pumps were set to turn off when they reached £98. Which must have been what happened.
If your staff had bothered to explain that the whole situation could have been resolved. Instead they were rude and disrespectful.