Did you select payment from your available balance on checkout ? Also, did you place multiple, consecutive orders for the same domain ? Does not look like a good idea. Is this a name that you let expire ? Maybe there is something I don't get quite right.
I guess dynadot add a crontab to process all delete order and new domain order in queue every 30 minutes since yesterday. Because I faced the same problems as same as you.
----- My Comment: I prefer prompt registration via Web interface instead of putting my domain order in queue.