Fraud at dealers

[Albell]

Hi, so I recently bought a new vehicle from a well known dealership, they offered me their "members club" which had some benefits that had no use for me, so not worth the money. After picking up the vehicle and getting home I noticed I'd been charged for it regardless. I phoned them up and was fobbed off with it being an 'admin fee'. Despite it not being on my original order which I have a copy of, and being told by another salesman that it shouldn't be there, they are still not refunding it. Given that I have been lied to I believe this is fraud, what is my next step?
thanks in advance.