WHERE IS MY PAID UP LETTER? THIS ACCOUNT HAS BEEN PAID UP MONTHS AGO!!

This account has been paid in full, albeit under duress. I effected payment of the FULL AMOUNT stipulated as being due and owing on your statement emailed to me on 7th February 2019. Proof of such payment was emailed to you on 11th April 2019. I have requested a PAID UP LETTER and as at date hereof am still waiting for same. Please provide me with the required PAID UP LETTER and please instruct your collection agents to refrain from harassing me. Their harassment is unacceptable, frustrating, stressful and unwarranted, as this account has been PAID IN FULL!! I await your urgent attention to my query and expect to receive the PAID UP LETTER in my email inbox today!!