Pathetic service and Cornubia Shell garage

Day before petrol prices go up the petrol attendant filled my tank and i paid cash and then wanted to redeem my V+ rewards to fill more and he said the card machine was not working, allegedly the V+ was not redeeming when swiped, I also noticed that my V+ balance didnt increase. The cards are a big let down. He filled the second amount of petrol before swiping so the petrol is in my tank and I was out of cash. He refused to let me leave after doing something that was his fault and I told him to call the manager then to make an arrangement as I am a regular at that branch. He claimed the manager was not there and refused to let me leave as I was still owing. I had coins that amounted to half of V+ rewards amount that was filled but couldnt be redeemed. So I was forced to use my card which went down to almost 0 when I filled. Big inconvenience and frustrating service, the attendant never bothered to apologize and was not helpful to the situation at all