The way I understand it, whether by phone, email, fax or in person...you have to authorize the repairs. If you hinted for them to fix the truck, they may have understood that to be authorization and ran with it.

Was there not an estimate provided before they dismantled the engine?

Was there a compression test?

I take it the warranty has expired?

If you did not authorize the repairs (the SM may fight you on this); then trade it in on the spot. I just went thru an issue with my truck and traded it in without authorizing repairs and received a reasonable trade in value. Actually, it was a little higher than what was offered by other dealers when the truck was running.
I haven't slept better.

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