i would go to the managing director, explain your loosing faith in their dealership, ask to go over the records of the repairs. IF THE REPAIRS ARE NOT AVAILABLE IN PRINT, then it is time to write them off permanently. If thy can go over the issues, explain what they have done, explain to you what the codes were, etc then make the decision from there about whether you would trust the dealer with another attempt to fix it. BUT as it stands now, I would be suspect of the dealers actions, even when my car is repaired for free, I receive documentation of what was or was not done. I would hope you could at least resolve to getting the paper trail to take to new mechanic since the previous codes have been erased and such.