I just picked up my car after service. I left it f...

I just picked up my car after service. I left it for the weekend. Car was beautifully clean and everything checked out well. However, when then cleaned my car they removed my drivers vinyl mat and on the passengers side was the paper dirty mat and paperwork from another customers car service.
A. German 2002 Toyota Rav
I did not notice it until I got home.
I tried to call when I got home to advise but the phone kept ringing with no answer...Perhaps the lines were down.