Linkage to the injection pump stuck sitting so long? Easy fix just verify by pressing the pedal or having someone else do it while the lever on the injection pump is watched.

This is not a drive by wire or electrical throttle is it? Even then the mechanical portions of the set up may be stuck or the control at the pedal end oxidized. I would not take this issue to a dealer unless you have deep pockets from what you have quoted.

I have stood in lines at service places for this brand at dealers. What I have heard being paid for biils was ridiculous.