Disgusted in the customer service that I have been receiving

I am so annoyed with outsurance on the 21st of December I called outsurance saying that my rental car agreement needs to be extended as the panelbeaters have confirmed that my car will only be ready in February. I was told that by the guy I spoke to that he will make a note of it but I need to please call again a week before I need to return the car. I called last week Thursday I was told by the lady that she will send it to the management team and call me back. To date I have not received a call. I decided to call again today. The lady I spoke to told me that she will get back to me within 10 minutes (this was at 9:30) I am still waiting. I called again at 13:00 got told the same story that they will call me by COB. It is 19:30 and I am still waiting. I notified outsurance about this well in advance and not leave it to the last minute. Today I received 2 messages to say that the car needs to be returned by Wednesday otherwise it will be at my own cost. This is not on me this is on outsurances ****py service that I have received!! Please call me tomorrow so this can be sorted out by the end of tomorrow I am tired to call after you. I have done my part - now do what you are supposed to do