Allstate insurance?

i have all-state car insurance and i was in a wreck about 3 weeks ago and with my claim they said they will repair all body damage caused by the wreck and what ever Mechanical damages there are well in the wreck my brakes failed so at about 5 or less mph i threw the car in park an i still skidded and it the car in front of me when i talked on the phone they said the transmission would be covered today i got the car from the body shop and they went behind my back and all-states back and sent the car to an Half *** motor shop they said the trans was just burnt up not damaged so now all state wont even cover the transmission and the car drove fine up till the wreck now it wont even go 2 mph any help ??