Problem with aircon installation

I have bought a Samsung aircon from Aircon Experts (A division of N.H Air Solutions) with installation last year November. Since the installation the aircon has been making a noise, like something is stuck in the fan. <br> I have contacted Mr Viljoen, the owner of the company, numerous times complaining about the problem. <br> There has been technicians at my house on 3 different occasions to fix the issue, but nothing has changed. <br> I have contacted Mr Viljoen again 3 weeks ago to tell him they should either come and replace the aircon with a new one, or I want a full refund. <br> He has not been to my house yet, all he says are that they are busy. <br> <br> They are an accredited Sumsung Aircon installation company, according to their website. <br> <br> Can someone please tell me what the next steps are to get this problem sorted, as the product is still under warrantee, I want it to be replaced, but I am not going to pay for the installation again, as I have not received a satisfactory service the first time. <br> <br> What are the process to become an accredited dealer of the product, and what can be done to a dealer not holding up their end of the deal, as this is forming a really bad impression