Disappointing service from Renault

My name is Ronny and I took in my car to Renault Centurion on Monday the 28th September. The car had a gearbox problem which is to be covered by warranty. However, 8 days later no concrete work had been done to ensure that I receive my car back. To make matters, no courtesy car will be provided to me unless warranty has been signed-off by Renault SA once assessment by their technicians is done. Renault centurion is blaming Renault SA for the delay on the sign-off, and has advised me to call Renault SA to have this expedited. I also spoke to a guy by the name of Reggie at their call centre that hasn't been faithful with his commitments. On the 2nd of October he said he'll get it touch with Renault centurion to sort my problem out but he never got back to me. I called him again on the 06 of October to follow up