Lower belt squeeks half on an off pully

1999 neon with 376,000. Lower belt did squeek because of leaking radiator hose that was replaced. Belt still squeeked and I noticed it was only half on pully. One mechanic said it was possibly a tensioner, another said it was multiple problems with water pump, timing belt, pully, three days of work and $800 at best. I finally took it to a dealer and he said the pully had been bent by replacing the lower belt when last water pump was replaced so he replaced belt and pully and showed me the parts that had "thrown a tooth." The squeeking stopped but the belt is still only half on the new pully which has made no difference. Nothing was said about any tensioner by the dealer. Suggestions?