Claim management disaster

I had a motor vehicle claim and Momentum appointed NetAsses as assessors. The assessor went out and send a report with the quotation. The claims administrator from Momentum contacted me and send me the report for approval . First of all did they only do an inspection on the right hand side of the vehicle and put the two tires and rims on. I rep**** to the administrator that the left hand side was also damaged. I also told him that the quote for the tyres are too low as my vehicle are factory fitted with Run Flat Tyres. That is maybe the reason they missed the left side as the tyre are damaged, but you cannot see that it is flat. Now, 6 weeks later, I received my vehicle (yesterday) and it has normal tyres on it, with the front and back different makes. I made numerous calls and mails to the insurance and assessors, but to no avail. It is the responsibility of Momentum to sort this out, but my calls were never returned, or the call agent will tell me "we will get back to you" for which I am still waiting. This was my worst experience ever with an insurance company. I even tried to get contact details for a senior manager but was not able to get it