engen palm service station incorrect fuel in my vehicle(6 months down nothing has been resolved)

it has now been 6 months that I am still chasing my tail regarding the payment for the repairs that my vehicle had to undergo due the *********** staff at the above mentioned service station. I have a chain of e-mails going back & fourth promising payment will be done or has been processed. This is the kind of ********* franchisees that Engen has representing their brand.