Faulty part?

I purchased a clutch kit from the durban central branch about 2 months ago for almost R3500. My car is experiencing now the same issue. I took it into a gearbox specialist thinking it was the gearbox however upon checking they advised me it's the clutch. To just check my car at a dealership that is close to home they want to charge me R800. I am not very happy and was told to visit the branch, however I did email the person who sold me the part but since it's been over a month and no response.