Not taking Responsibility / Defective Workmanship

I had motorcycle rims powder coated by TMS. After a lengthy process to get the powder coating done (The rims went back and forth because of poor workmanship) the front rim was compromised due to removal of excess material from the rim where the brake discs mount. This caused the brake discs to warp and resulted in the safety of the motorcycle being compromised. TMS is unwilling to make good for defective workmanship on their part and refuse to take responsibility. The rims and the discs needs to be replaced at a cost of R20,000 for my account.