Rogue keeps throwing belt.Have changed the tensioner pulley but still having problem keeping belt on

What is your question?

The first time it threw the belt we replaced with new belt. But any time you turned the a/c on it would squeal loudly. Took it to a mechanic he replaced the tensioner, and it still chirped. took it back and he cleaned pieces of belt out of pulleys. then today it just threw the belt off completely. I am stumped.

How long has your 2011 Nissan Rogue had this problem?

1 month