I've seen two journals from two different people about this already, so I'll help spread awareness.
There's a bug going on in deviantART that when you try to buy something for points or send points over to someone, the points won't show up as sent on the first go. They'll show up as sent later on, and however many times you try to send the same amount of points, dA will send them all with a delay. So either you send the points once and wait for the transaction to show up, or you refrain from buying anything with points until the issue is fixed.
This has been a PSA. Hope it helped!