What to do when someone is blaming me for an accident that isn't my fault?

I was stationary in a right lane waiting to turn right into a street. There was no one behind me when I stopped, but as I began to turn when it was clear I suddenly heard a horn before being rear-ended. After getting the vehicle off the road I asked the other driver what happened and his response was "I think you were turning and turned too slow".Police were not called as he lead me to believe he would make a claim through his insurance and let me know the claim number. The next day I was given a not-at-fault replacement car through right2drive. Upon receiving the claim number I rang the RACV only to find out he made a claim for compensation saying that I was at fault.First he said I was doing a U-turn, then it was I was turning over an unbroken line, finally I've been told he says I was doing a U-turn from the left lane. The damage is on the rear driver’s side. I've got quotes all saying the car is a write-off. Due to me telling RACV what really happened it is going under dispute (he has insurance, I don't).Right2drive not at fault replacement vehicle states I have right to vehicle until mine is fixed/matter resolved. Because the claim is going under insurance, right2drive is terminating the car due to other driver and RACV saying it’s my fault. I live 45 min from work and require a vehicle for my work. Do they have the right to do that? What can I do to resolve this?