Odometer stopped working

Hello, I have a 1996 Ford Explorer XLT, V6, with 124850 miles on it. I recently had it serviced/repaired at the dealership. Odometer, etc. All worked fine when I pulled in, I monitor my gas mileage so it's something I notice. Part of the work performed was removal and replacement of upper control arms & inner tie rods, alignment, oil change, tune up, new filters, cooling system flush service, and a new steering mechanism/column (my cruise control buttons had deteriorated on my current steering wheel, they offered me one "on the side" that had newer/better buttons - that was not included in my invoice, I had to pay a mechanic on the side). I noticed after pulling out of the dealership that my odometer and trip counter were not working. Speedometer IS working. I took it back and they are saying none of the work performed on my truck affected the odometer, and they want to charge me over $300 to "fix" it. I guess my question is, could any of the above work/service have caused this? I thought it would be a simple "oops we forgot to reconnect that" or something, instead it turned into "give us more money, we didn't do it" They told me it's the speedometer mechanism, even though THAT is working? Thanks for any feedback.