Hired car extension

I reported car accident while i took my car to Toyota, Auto and General fetched it to their own place and later to repairs chosen by them. I was given hired car for 1 month. I was called by the repairer that the parts will be available by the 19th November. I am expected to return the car today 8 November and when i called them to ask for extension I was told it cannot be done instead i need to talk to repairer myself to ask them if they do not have a car for me. I tod them that they are to be the ones to talk to them as i did not take my car to that place. They promised that someone will call me i cannot return the car when i do not have a car to move around. I would like to get the extension because i know they do it to other people.