Faulty tyre - refused replacement

We bought and took delivery of our BRAND NEW Renault Duster beginning of June 2015 (Approx the 3rd or 4th). After 2 weeks or so of driving it, a petrol attendant pointed out a bulge in the left rear tyre. We called the Knysna Renault dealer and they said they would get back to us. After another week we called again, was told that Renault doesn't offer warranty of tyres but they will advise the procedure, a few days past again, so we went into the Knynsa Renault, were told to take the car to any Speedy, Speedy Knysna said no it doesn't work like that. So Renault Knysna sent us to Renault George, who took photos of the tyre and never came back to us again. Another week later we went back to Renault George who then directed us to Tyger Wheel and Tyre. On their first look at the tyre they said that Continental will say it is accidental damage so we shouldn't bother! We have never even hit a curb let alone a pot hole with this tyre, how can it be accidental damage!?!? So we insisted they send it to Continental who refuse to replace insisting it is accidental damage, which is impossible!!! DISGUSTING! I WILL NEVER BUY CONTINENTAL AGAIN AND WE OWN A TRUCK & TAXI FLEET TOO! BUYER BEWARE!