Renault Clio Gearbox Fault

Good Day,

I would like to report a concept I do not understand by Renault and how they tend to their customers. I bought a Renault Clio 900cc Turbo Expression in September of 2015. I am currently experiencing a mechanical fault with the car. The car is emitting a vacuum like noise when in motion from gear 3 to 5. I took the car in for it's interval service at Renault Northcliff and pointed this issue out the technician and we proceeded to go for a test drive. The technician pointed out that there is a fault with the transmission and that I would need to leave the car with the for a week or two, depending on the outcome of their assessment as well parts availability. The service representative noted that should the gearbox fail it would be at my cost to fix even though the car is under warranty. I have no qualms with leaving the car with the dealership to be fixed under warranty, however, the issue arises when the dealership refuses to borrow a courtesy car for the fault on their product. My question remains as to what mode of transport am I to have when they are busy fixing a fault with their product?! I refuse to make any other form of arrangement to getting a courtesy car outside of making an arrangement with Renault; a manufacturing fault of their product shouldn't be to my financial detriment! This is their product that is faulty and it needs to be fixed!