POOR SERVICE FROM WORLD REMIT

I have made a transaction with World remit on Sunday the 8th of December, today is the 16th of December- a week later, the transaction is still not cleared. They have rather cleared the transaction I've made on the 11th of December, still to the same recipient and was cleared the same day. I keep calling their line and they would keep me on hold and say they are still investigating and will provide me with feedback on what their client says, no one got back to me to this day. This is really frustrating because my recipient needs the payment and is now harassing me. The money went off my account already but I don't understand why it takes them forever to clear it on their side. This is a week later and no professional communication has been made. This is by far the worst service I've received.