DriveTime Automotive Group review: The gap they offered me and that I signed up for has not paid the total loss of my car.

I bought a car from DriveTime in 2016. I signed up for the gap insurance with Aeverex insurance which was recommended through DriveTime. I recently totaled my car a month ago. My insurance company paid their portion out 2 weeks ago. I recently received a letter from Aeverex stating they are only paying $800.00 out of the $4000.00 that I still owe. I have been given the run around as to why they can't pay the full balance. Isn't gap supposed to fill in the gap after a total loss?! I am very upset. I have 3 children and a full-time job. I have to figure out how to get to work and my children to school every day without vehicle. I am not able to get a car until this balance is paid in full. I do not recommend DriveTime or Aeverex at all.