roy's auto repair took money to fix a problem on car and left with same problem i came with upland California

my 2005 buick rendezvous was jerking into first and second gear and roy the mechanic test drove my car and told me that my lower motor mounts were broken. he gave me a price of $250.00 and i agreed, he said that it would take about 2 hours. after about one hour he test drove my car again and said that it was ready. when i went to the window to pay he had dropped the payment down to just $200.00. he told me when i'am driving not to take off fast but do it slowly so that the gears would have time to change. i did what he said but found out it did'nt make any difference how i drove my car was doing the same thing it was doing when i brought it to his shop. that was on the 16th of march,2015 and here it is three days later and i cant get in touch with him.he did have me to write my phone number down before i left and now he wont answer the phone. i finally took my car to Aamco on 3-18-2015 and found out my problem was inside the transmission. he should not have taken $200.00 knowing he had not fixed my car.