Tanner Transmission actual charge much more than estimate Layton Utah

I took my truck in to Tanner Transmission for a simple check up and came out convinced that my transmission was shot and that I wouldn't be able to make it any distance with it.

I asked for an estimate on the repairs and was told it would be anywhere from 3-400 up to 900 dollars. I then authorized the repairs. They gave me a date they would have it done and then told me they would call me. Of course they never called and I had to call continually.
Once it was done I went to pick it up and was told the total was about 3200 dollars. I had a trip coming up that same day and had to pay it to get it out of the shop. Not only that, but its never been worse. I now know that there was nothing wrong with it in the first place. I've taken it back several times and they insist that everything is fine and that there is nothing they can do to fix it. Terrible service. Terrible ethics. That place needs shut down. I hope they go bankrupt.

Joseph
Layton, Utah
U.S.A.