How did you leave it with them before the repair was made? Did you specifically give permission to do the repairs they did? Did you leave it vague (as in 'do what you have to')? Or did you tell them you wanted to be consulted prior to repairs being performed if they fell outside certain parameters?If they performed an unnecessary repair without consent then you may be able to take legal action if they attempt to charge you for it.
11/2/14 at 11:02am