Arista insurance threats on third party claim

Hi

I had a van reverse into my car recently and they admitted liability at the scene and subsequently.
I have 2 witnesses who have also confirmed this.

The firm who owned the van phoned me and told me to go through my insurance which I have done.


Now the firms third party insurance have called me and told me that they will not pay any differential between the claim and what they could have provided the same service for. The example given was £117.51 for a hire car they could provide for £39. The differential of £78.51 would have to be paid by myself for everyday I used the hire car, the only way to avoid this would be for me to let them handle the claim. The same policy would apply for all repairs and any incidentals.


The third party insurance call said this was due to the credit agreement that I would have entered into with my insurance claim management company even though my insurance would not have told me about this at the time it was the case.


1. how true is this?
2. if its not true how are they allowed to do this, the call was polite but with very threatening\menacing undertones.

3 if it is true why is this not clear in the process and paperwork from the claims management company?