Credit card account

I am quite upset with this collections agency as they have been contacting me about my account without fail monthly, and after accepting a settlement discount and paying up my account, i am.being ignored. I want my account marked as paid up and i want my paid up letter please. I have messaged on whatsapp several times i get no reply i have emailed as well to no avail. Please mark on swordfish that it is paid up and remove from my transunion credit profile.