repairs done over and over and still not right

I bought a vw caravalle a year ago in centurion and in the 1st few days i notice that it's using lots of oil. I took it back and wanted to cancel the deal but they promised to get it sorted and fixed and i will have no problems. After 4months and not n car even to drive with because its not there problem so i was told by management, they replaced the 4 pistons. In January i noticed that the caravelle was using oli again. I took it back and they started testing again and again 4 months later and again no vehicle to drive with because its not there problem...i got ot back on vryday 12/06/2015 after the engin has been replaced. This morning a towing service came to pick it up again becouse its smoking like hell and i didn't even take it out the yard. I live in witbank so al the way from centurion they came drop it of they want to tel me they didn't so it smoking. I am really sick of there lies and pathetic service. I have my caravalle just more than a year and 7 months there of it was standing at vw centurion. Please help i hade enough...i can not see how these people can fix my vehicle because if they couldn't even fixed it the fist time.