Product: Payday loan, title loan, personal loan, or advance loan

My loan has been set up on auto debit since the start. It's due on the XXXX of each month. 
The May payment did not clear and on XX/XX/XXXX I logged into my online account and requested to pay the balance off in full, which I did with a debit card so it was an immediately payment. I began receiving notices within the next few days stating that I have a XXXX payment coming due on XX/XX/XXXX. I emailed the company about it inquiring why I am getting these notices since I already paid the loan off. I received an email from XXXX XXXX on XX/XX/XXXX stating that my obligation had been fulfilled and there was a XXXX balance. Then I got several more texts and emails claiming that I still have a XXXX payment due. I called and spoke to a lady who claimed she would open a ticket but would not send me any sort of confirmation of this, to which I requested a manager. Someone named XXXX argued with me for XXXX minutes about why my online payoff quote wasn't accurate and that the company gives you credit for payments even though they haven't posted. Which makes ZERO sense. 
HE claimed he would open a ticket with the accounting department to see if they would waive the open payment due for XXXX even though there never should have been another payment after the loan was paid off. 
I waited several days for a call back which did not come so I called the company again. This time I talked to someone who said there was no update and when I asked to speak with XXXX again I was told he was unavailable and that I could not have an email or phone # or voicemail for him. Okay- so several more days go by and finally today, XX/XX/XXXX I get a call back from him claiming that I was denied my request to have the XXXX payment removed and would be obligated to make that payment or it would be reported as 30 days late to the credit bureaus in the coming weeks. I demanded his last name, which he claims is XXXX. XXXX XXXX. Then I asked for the manager of accounting who was responsible for this decision to which he claimed is someone named XXXX. Before he would give me her last name he started stating to me that he did nothing wrong and if I wanted anyone management names, it was public information and that I should go look it up. He gave me XXXX last name of XXXX before cutting me off and then hanging up on me. Now I have been forced to pay the additional payment to keep it from being reported as late and I already paid this loan off a MONTH AGO. This is unfair, deceptive and ridiculous to take such advantage of a consumer who paid the obligation in full, as noted by this company the day the debt was paid off. 
I have the receipt of the payment made on XX/XX/XXXX, the email from their customer service person showing the loan was paid in full, I also have the receipt from the additional payment made today and another receipt from the website showing the loan is paid in full. 
The worst part about all of this is that the website does not allow me to login and look at the payment details of the loan once it's paid in full so I can't even see the balance breakdown or anything on the account. Regardless-the website gave me a payoff quote on XX/XX/XXXX, that's what paid, we received additional confirmation on XX/XX/XXXX that the loan was paid off and a month later i'm being forced to send these people more money. This is disgraceful and predatory behavior!