Where to Complaint against a Mechanic

In April 2011 when i did periodic maintenance (changing of oil and filter) for my car, a mechanic charged me for changing oil and filter (invoice available) but as he went down the car he did not change the filter and kept the new filter with him (may be for resale)

I had written on the previous filter which was changed earlier the mileage (for one time only and this was the first time in my life). Unfortunately, at the time of change (as everybody does) I did not ask him to give me the old filter to see whether he actually changed it or not. Later on when i was doing my car maintenance at another shop and the car was lifted up I saw the old filter with the old mileage written on it which is the proof that he did not change it and a proof of theft also.

I want to know where to make a complaint against this culprit and thief.

Should I go to police or should i complain to consumer protection department. The problem is that police knows arabic only and I may not be able to explain fully.