run flat tyres

My brand new Mercedes benz C250 comes standard with run flat tyres. On Good Friday, on our way from Pietermaritzburg to East London, we had a punctured tire about 80 km from pmb, in Ixopo. I remembered that I have road side assist, and immediately called. To my absolute disappointment, they were unable to assist us as they do not have the equipment to help, and they do not have new tires. So be aware, Mercedes benz road side assist means NOTHING! We're in Africa so just tie a tire to the roof!