a standby boarding pass is issued to get you through to the gate merely as a way of saving time once check in closes and all figures are collated. It is possible you could have been turned away at the gate as no seats available.. Had there been seats available you would have been accepted at the gate and boarded immediatley, instead of having to go through the check in procedure at the last minute and rush to the gate. The following day they would already know if seats were available or not, and in your case obviously not, because they would collate figures from the previous day check in, therefore not issue you a boarding card because there was no point. A boarding card does not give any legal entitlement to board an aircraft, merely to enter an airside area as a passenger.
Hope this has cleared it up for you and you made it back eventually
TM
