Promotional card used for bill and not showing as used on my bill

I tried to do a split payment to use the promotional card on a majority of my bill and a different method for the remainder. After going through the process, I got a confirmation number of a $170 payment towards my bill and I need to pay the remainder by January 4th. I go to my bill to pay the remainder and it says there's no credit pending on my bill and I have to pay the full amount. Is it just going to take a while for it to be credited to my bill and THEN I can pay the remainder or did it not go through and the confirmation number is a red herring of some kind? I'm a bit confused at the moment. If worse comes to worse, I'll end up either calling in the morning or going to a local store to try it again, but I don't know if my promo card is now used up or not also. A bit of a mess, at the moment.