Usually with collection only orders the buyers get a collection code and once this is entered the funds are released after 24 hours. However if the order had postage stated then it would need to have tracking applied to show delivery to have the funds released. As there would be no tracking as you have advised it was collected then it likely the funds would be automatically released after 14 days. See the details on the policy here.
Do you know if simple delivery was used for the postage option?