Momentum Insurance has no focussed sense of client service

Momentum Insurance has no focussed sense of client service. I can’t seem to escalate my query to a senior manager that can resolve my query. This claim is non-driveable, meaning the car could not drive as there were mechanical issues at the time of the accident on 8th December. However, the assessment report lists no mechanical issues, I have pointed this out on numerous occasions when speaking to a call centre agent at Momentum claims department. Claim was only approved for body work and no mechanical repairs.