bad service and *******

I bought a Audi a3 in april at Jakaranda motors and was told the cars is well looked after and is a good quality first they sold it to me for 180 000 and later i learnt the car isnt even worth 150 000 it is the first car i have ever bought and dont have experience in buy cars and they took advantage of that and ripped me off and the car has just been giving me trouble since i bought it , its more at the mechanics that i drive it ive had to replace wheel bearings, the turbo, the water pumps and turbo pipes its just been a mess up, i hope someone important reads these complaints and takes action and now i cant sell the car for because of the huge anount they asked me for.