i don't blame you one bit for being upset and its not up to you to cover the cost.
this happened to me in one wedding. Good thing my friend was in the wedding party with me...the brides 3 other bridesmaids were from back east so everything was up to me and my friend so everything we purchased we kept receipts and kept in touch via email and gave them up dates on how much was owed....it was a little drama at first but worked out in the end