I had a infuriating experience with Xoom recently, where I initiated a transfer (type: bank deposit) on Thu Feb 26, 10:42 PM PST. The bank account belonged to the aunt of my recipient.
After 6 hours of seeing the transfer sitting in the queue with status "Transfer in Progress, " while my recipient was frantic because the funds were needed for a medical emergency, I emailed Xoom Help to see what the hang-up was, but received no reply.
Almost 20 hours after I initiated the transaction, with still no progress, I cancelled the transfer. This was Fri Feb 27, ~6:00 PM PST. I then initiated another transaction (a cash pick-up this time) to another go-between of my recipient.
Can you guess what happened? Yep, both transactions were paid. The first one was completed almost TWO DAYS after... AFTER!... my cancellation request. So it ended up costing me twice what I had intended to pay.
Yet when I complained to Xoom, they had the audacity to claim that "Your transaction has been completed before your cancellation request."
Object lesson: Never start a replacement transaction until you're absolutely certain the previous one was canceled and your money refunded. These guys have no soul, and they take absolutely no responsibility for their screw-ups, even lying if necessary.
Better yet, use Western Union.