Welcome to the Quilting Board!
In my life I'd had so called repairmen tell me a number of times that what I wanted fixed was not worth fixing. In every case they lost any future business I might have given them, and I got PO'd and fixed the thing myself. Phooey on 'em.
If no one has answered you yet...check the lever next to the bobbin winder. One of the positions causes the machine to to run in reverse. (I am playing with mine and found this)
In my experience, people who work on machines prefer to work on the ones they are familiar with.
If they work on vintage machines they often will automatically say a plastic one "probably has a broken gear, don't bother trying to fix it." And if they usually work on electronic machines they "don't want to mess with those old ones".