Take the bow into a local authorized Bowtech dealer and have them check it out for you. If it turns out that you do in fact have a cracked limb then Bowtech will take care of you as quickly as the dealer gets your bow shipped.

A bow that is three years old having a cracked limb isn't as suprising to me as one that is brand new, so don't feel too incredibly down because of it. Bowtech will get things straightened out.