Before calling, you have two options and ought to carefully research them. The auto rebook you received is simply a means of assuring that you are holding something.
1. You may cancel for a full refund and then book whatever you want.
2. You may ask AC to reroute you. No guarantees that it will do so, but you should be prepared with your preferred reroutes in hand as there is no guarantee that what works when you call will work an hour later.
If you do have expenses, check your travel insurance. It is not likely to cover anything this far out, but some policies do.