Shell has messed up vehicles with contaminated fuel

Shell Northern Drive in Phoenix Durban filled contaminated fuel into my vehicle. This happened about 1 month ago. My car began to smoke and I took it back to the garage. They in turn told me it was the Transporter, Tanker Services that had decanted this contaminated fuel and they are dealing with it. I was then told to go to Bosch Mount Edgecombe. My vehicle has been there since then and Tanker Services was messing around. I have been without a vehicle for more than a month. My vehicle is now ready but Tanker Services has not made the payment to Bosch Mount Edgecombe. So they will not release my vehicle. I have contacted Steven from Tanker Services but he is of no help. He says he will follow up with payment but nothing has been done. I need my vehicle urgently as it is not any fault of mine. I have also contacted the garage and they did inform me that there were a number of vehicles affected. I don't know how Shell uses a Transporter that messes around with Shell's customers. This is a complaint against Shell as my vehicle was filled at a Shell garage. Shell needs to take responsibility and fix the problem and not pass it over to the rest of the parties involved. I will never use a Shell garage in future and the public needs to be made aware of this.