computer bytes broke my computer pleasant grove Utah

I took my computer in to replace the keyboard the letter M would not type he ask me to pay in advance & if I paid cash he would not charge tax, it would be done intwo days, three weeks later he claimed he broke the charging port putting it back together & he order the part would be in in 2 day s at no charge then one week later he returned it & said he could not fix it and I told himI would take it to apple to see how much to repair & return with the bill but it can not be fixed & he willnot return a call or email or will he open the door of the business please help he was taking computers in left & right when I was there & if he is not collecting tax he is commiting fraude