After repair problems occured

Taking my vehicle to mahindra vaal for repairs July 2015, they repaired the following:<br> replace rocker<br> chain guide and tensioner<br> repair crankshaft nose end<br> replace engine bearings<br> crankshaft timing gear<br> crank pulley<br> repaired fan-belt tensioner bolt.<br> <br> After the above mentioned, a vibration occurred.<br> The car was taken back 3 times. After each time new problems occurred and the vibration wasn't fixed.<br> A new keyway had been cut on the crankshaft nose end.<br> <br> I went to the engineering shop who had cut the keyway, and they said, they only machine the crankshaft, they don't balance it.<br> <br> Mahindra told me they sent the car to that engineering shop to balance it after the cut.<br> Mahindra sent it again for a 2nd time to look at the vibration, that engineering shop told Mahindra that the keyway had been cut too shallow, and they then cut it deeper.<br> <br> After that, the vibration got worse.<br> I took it back the 3rd time, waited 2 weeks, and there is still a vibration.<br> I told them the 2nd time, the crankshaft must be balanced, and that engineering shop don't do balancing on crankshafts, after they've charged Mahindra for balancing.<br> <br> I myself took the car to balance the flywheel and recheck the prop-shaft.