Being that you only ordered the m22's two months ago... I would call axiom and ask them if there is anyway you can pay for shipping and return them even though you are outside of the 30 day trial period. If you tell them you will place an order for the m80's at the same time they might cut you some slack...

worth a shot at least

Dopn't know about your receiver and the m80's though.

What yamaha do you have?