Terribye quality, Bicycle Still Damaged

I bought a Mongoose Mountain Bike from Sportsman's Warehouse, Pavilion. I had to return it as it was faulty, I got a replacement which they then had to send in for repairs and after that, it was still not working properly. I then sent this one back and got another replacement. My new bicycle is still giving me major problems. Sportsman's offered to have it repaired at Hatton's Cycles, Glenwood. Unfortunately Hatton's did not do a good job and did not give a proper assessment of what was wrong with the bike. I had to send it back twice and then I got told that the braking system is just a poor quality one. I then took the bike to Adams Cycles for a second opinion and I was told that it is an excellent braking system but that this one has a factory fault and it needs to be replaced at an approximate cost of R2 000. Why didn't Hatton's tell me this and I could have had Sportsman's pay for proper repairs. I am now stuck with a R6 000 bicycle that I cannot use as the brakes are completely stuffed and Hatton's also stripped the bolts. Hatton's did not fix it properly. Do I need to contact my lawyers now or will Sportsman's replace my brakes so I have a working bike.