Pryor's Garage Ltd in Truro

Unfortunately my car went back several times after I had some body work done due to pieces of body work coming loose, over a quarter of a tank of fuel was used on its first visit, but the staff assured me it had not been driven?
The third time I went back the member of staff behind the reception desk became very rude and claimed it must be something I am doing causing the wheel arch to become loose? After taking it to another garage it appears no clips were used to put the arch back on, only some thick glue? However on my invoice I was charged for clips?