Gomechanic Car Service - Incorrect product

So i booked a comprehensive service with go mechanic with an upgrade to W** synthetic oil ehich costed *k extra as i have a vw passat which required synthetic high pwrformance oil. I knew all the mechanics make a lot of money from using low quality parts so i opted for wait and take the car service.The mechanic went out to bring some filters needed for the car and so I went out to get a bottle of water.I was back after merely **-**sec and till then the other mechanic was filling the oil from a can which had a sticker or w** synthetic oil.Gomechanic executive was clicking the photo while the oil was getting filled for a proof.The oil level was a little low and the mechanic when inside again to bring some oil when i noticed that he was literally using oil from a barrel of castrol oil.Go mechanic charged me *k extra over the regular service for the oil uograde and the gomechanic executive with the mechanic were fooling all of the customers.