I had this similar problem last week. I cancelled two tickets, asked for them to be redeposited, while I required the miles back to ticket a reservation on hold.

Nothing happened for 4 days, and I called back more than once everyday to ask what was going on and all the phone reps could just tell me to "wait", even though the hold on my award was expiring soon (one agent argued with me about the timezone - online it clearly showed Malaysian time, but she kept insisting it was central time.)

Eventually I called again and told the whole story again to the next agent. Agent puts me on hold for 10 minutes, and boom - the miles are back in my account with an apology for taking so long.

It sucked having to get the runaround so many times, almost costing me my redemption seats. You really have to get lucky sometimes to find a representative that is helpful and caring enough to get this stuff straightened out.