Urgent Paid Up letter required

This is my third review on Discovery. So after months of request for a statement from the Discovery lawyers(SSDA) for my outstanding balance I recieved the statement last week and I now have paid my outstanding amount to the Discovery collection attorneys. They(SSDA) confirmed that they have received this payment but I must wait 21 business before they can provide me a paid up letter. I have contacted Discovery via email yesterday and received only a email with reference number: *** but still no word from Discovery. I urgently need this paid up letter to clear my name on ITC. This is urgent.