The worst service ever

My car went in for repairs two weeks ago and I was promised to get my car back in 5 days. When I heard nothing on the 5th day I phoned the panel beater only to be told that they're waiting for authorization from the Miway. Three days passed and they hadn't received the authorization. I phoned Miway to find out and everyone I spoke to told me they'll send an email to the assessor which I assume was never done, because there was no feedback. I then sent an email to a guy who helped me initially with the claim and he couldn't help but emailed the head of assessors and only then did the panel beaters get the authorization. My car is still at the panel beaters, and I had been given a rented car which is due back today. I phoned Miway to ask them to extend the rental period until I get my car back, but I have been told an email will be sent to whoever and I'll get a call back before 3. It's now almost 3pm and no call from Miway, I have to take back the rented car at 3:30pm which means I'll have to use taxis to get home. How I'm going to fetch my daughter from school I have no idea. I am so angry.