Auto Insurance Help!!

Hello! I am currently in a pickle and I am needing advice on how to proceed.

I was recently in a wreck in which the back bumper of my vehicle got dinged. I collected the at-fault parties’ insurance and opened a claim. The insurance company is notoriously difficult to work with and it took several months to find a mechanic who would attempt to work with them. When I had the vehicle inspected by Mechanic A, the vehicle received a total loss declaration. The vehicle’s repairs were deemed to be above the cost of the car. However, when I had read through the supplemental report I noticed I was being charged for parts that were not broken or in need of replacement. I highlighted everything I considered questionable and scoured the area for another mechanic to offer their opinion. Mechanic B stated that I was correct, the vehicle was not a total loss once the unnecessary parts were removed. For example, I was quoted $1,800 for a new exhaust system that was not necessary at all. They re-evaluated the cost to repair it at $3,200 (vehicle was valued at $7,000). I reached back out to the insurance company to consult with the new mechanic and pursue repairing my vehicle, as it is not deemed an economic not mechanical total loss. They will not speak with Mechanic B. They are pushing aggressively to collect my vehicle, cut a check and take it to auction.

I have consulted my own auto insurance and opened a claim through them, after they had mentioned that they could repair the vehicle and pursue compensation from the other insurance company. However, I will have to pay a $999 deductible.

Is there any way to get the initial insurance company to simply just pay for the repairs? They have already written a check for approx. $1,100 that has not been used. I would truly hate to have $999 tied up in litigation for who knows how long. I just want my vehicle repaired.