Direct Axis - taking too long to sign off on a final paid settlement

I have made a final settlement payment to MBD Debt collectors on the 1st November already, this after years of unexpected financial difficulties. I have been asking for a settlement letter, and MBD keeps saying they are waiting for Direct Axis to sign off. This is holding my life back, as I need to clear my credit record.

Direct Axis must sign off and allow me to have my settlement letter please.