Car with engen problems

I bought a BMW 116i F21 Model in March 2015 and the mileage was about 77 000 km on clock, everything was fine until the car reached about 90 000km although the car was still under motor plan then i would take it in to a bmw dealer n all would be fine

After 110 000 km of having that car it started giving me nightmares, i approached the delear trying to find ways of giving back the car as a sale or trade nothing was successful n oviasly because the mileage was high now n the car had depriciated value we never got to the bottom of these car deal. I saved up money and took the car to a mechanic n he advised that the car needs an engine overaul and suprisingly to him it seems as if the car was overauled before meaning i bought a car that had an engine problem, The mechanic fixed it for me and everything was fine until now again the same thing happened with the car and im still getting the same explanations and advises with an engine problem. I am really frustrated now with these car coz i cant even sell it with the condition that its at and they need once again 35k repairing costs n i know n fully understand that once you sign the deal of a car the agreement n communication lies between you n the bank as the garage has done its sales part BUT i honestly regret and feel ********** for being sold a car that i do not enjoy driving for not more than 2 months with on going problems I had kept quite about it thinking i can tolerate it and maintain these issue but its really getting to me. Pharaoh Auto Investment please step in