One year, 12,000 miles if I remember correctly.
I assume that's also only if it's Honda dealer installed?
My point is that if there's a warranty, the OP needs to use it before it's too late. And even if there's not, the OP's current choice of shops is not doing him any favors. If the professionals can't figure out what is causing a slipping/mis-aligned belt, that's not a good sign.