"Reprogramming"

Where to begin? Paid $40 for diagnostic, also gave a down of $740 to buy parts. We called every week for the last month and was told they were still working on our truck. 1 month later...we receive a call to pick up our truck because they couldnt fix it. You would think that we would get our money back if the parts they put didnt fix the problem, right? Negative! They kept $516 because of "labor". They told us to take it to the dealer to get it fixed. So we are short $516 and with the lousiest verbal diagnostic. We werent given any paper indicating what the problem was just a receipt of what they charged.