Let me see if I understand: Two separate issues 1) zoom ring spins, but lens will not zoom 2) focus ring spins, but lens will not focus.
Both of these are manual issues and happen with the lens on and off the camera. Switches and contacts would have no impact. Since zoom and focus are separate physical gears, strange that they both suddenly stopped working.
While a different lens, I think this link will prove helpful:
http://www.lesliewong.us/blog/2008/0...8-70mm-repair/
These lenses have a 5 year warranty. But, if you are not the original purchaser (or don't have a receipt to say it was a gift), then you may want to try to fix it yourself.
Mechanics charge by the hour and they don't care if you bring in a bag of parts, or a single lump of parts that doesn't work.