Why won't allstate total my car value of car 25k repair estimate 20k what can i do do i need to get a lawyer?

allstate says they can only total it if repair is over 25k i;m like wtf? and on top of that i guess my rental policy is $20 and the car they igned to me cost 21.50 so i would have to pay difference then a week later they cancel my rental policy saying i'm responsible for my car rental now i'm tired of this do you think i should just get a lawyer and have them deal with allstate i live in california and it was not my fault on the car accident but unfortunately the other party has a 10k limit for repairs/ and damage any input would help thank you