By all means go and tell them you sent your $. Someone already said ... they may not have picked up their mail yet. My guild has POB and our treasurer picks up mail right before our meeting, so it may have been in their box awhile. Guild can provide many great learning experiences and new friends who will guide you into new experiences.
If you are fortunate enough to have a fairly large guild there will probably be many opportunities for small groups, outside speakers, trips to quilt shows ... the list is huge.
Hope you find a wonderful guild and take advantage of all the opportunities it offers.