Roof damage

[headlight]

Last Wednesday (April 27th) morning I dropped my MH off to an independent Fiat dealer to have a new clutch fitted.
I picked it up this afternoon and found that the roof has been dented on the rear drivers corner and the strip that joins the roof to the side is coming away.
The garage is adamant that it wasn't done by them but the damage wasn't there when I dropped the MH off.
Do I have any chance of getting anywhere with the garage ?

 

[Figaro]

have you got a photo of the damage to compare ?

 

[headlight]

No I don"t but I will take a photo next time I go to where it is in storage.
What you can see in the garages picture is glare from the grey shiny vinyl graphics.