The first thing that occurs to me is that the meeting may have been inquorate when the decision on the loans was made so, unless there were proxies left behind to make up the numbers, the decision may be invalid and you might have grounds for calling an EGM to reconsider the loan repayment period (or challenging the decision at NCAT if the committee refuses).
Apart from that, the easiest thing to do may be to go to your bank and ask to extend the loan or remortgage to cover the added amount.
But a challenge to the decision may be worth the effort – you can’t be the only owner with that problem.