Stansure - HORRIFIC SERVICE - NO CLIENT EMPATHY

On the 19th of February I registered a vehicle accident claim with Stansure Motor Insurance. My vehicle was not driveable and was towed from the accident scene. I was without a car. Car hire was arranged for me and I collected the vehicle the following day. For the next 3 weeks i never heard anything. I was only in contact with the assessor appointed on the claim (not from Stansure). My claim was only authorised on the 23rd of March, over a month later when my 30 days car hire expired. 10 days extension was granted following Stansure's realization of their delay on the claim. Yesterday the 10 days expired and I am being threatened with legal action if i do not return the car immediately. My issue is the car parts have not been delivered, let alone any repairs commenced. What I must I do without a car especially since the delay was not on my side. Can a route analysis of my claim be done? I am a single mother in need of a vehicle, it is not a luxury, it is a necessity. I do not appreciate being threatened by your Service provider, especially since this is not my fault!! I am starting to believe my only error was taking insurance with Stansure!!!