The Mag Specialist ruined my IMPORTED car part

I am very disappointed with the lack of care and quality of work produced by this company - The Mag Specialist. Firstly, I sent IMPORTED parts to be powder coated, and the colours were incorrect and did not match AND the buffing was wrong AND they coloured the wrong areas. I left the part where the buffing was wrong - there to be fixed and bought the other part home. I then sent the other part in again to be coated in the CORRECT colour because I was not happy, but upon collecting the part I noticed that hundreds of METAL sand blasting beads were embedded on the INSIDE of the intake manifold. Not only that, but the mating surfaces have been sand blasted as well when they are supposed to be mirror-smooth finished. I am disgusted in the fact that they would return the part to me in such condition that it cannot even be used. They interrupted me mid-sentence when I took the part in before this happened, and said they knew exactly what they were doing, when I was going to remind them what surfaces not to touch. I expected so much more from such a "reputable" company. I am livid! It cost me so much time, petrol, money, and now I cannot even use the part! I do not think they know what they are doing at all or the employees are not trained or supervised! This is unacceptable, especially because it is such a rare part.