125 Point Quality check

I bought a second hand i10 from Hyundai just over 3 months ago. The car underwent the 125 quality check. Or so they say. Less then a month later problems arrised. There came a funny nocking from the front left of the car and the radio goes on and off everytime I go over a bump or do something simple like close the cab. I reported this to the sales person and he had me come back on Level 3 to get the problems looked at. The then assured me thereafter that everything is fine. Less then a month later again, I am experiencing the same problems. I know the car is second hand and would not be perfect but this not what I signed up for. I will most likely be sent to the same service Centre again and a month later have the same problem.