Charged more than confirmed

I have brougt the assessment report with prices and parts needed to repair my car from third party claim to Brooklyn motorlab,Kobus from Brooklyn motorlab looked at car and report from third party.He confirmed everything and included 4 items missing from third party claim.Now the third party released the money,documents signed and motor is ready to be repaired,Brooklyn motorlab is charging 4000 more than the money from third party claim and nw I cant go back to the insurance and Brooklyn motorlab doesnt want to account to that.