Payment on my personal account :Ref no ***

I had personal loan and requested settlement amount and I paid the amount the same day and they still requested me to pay with phone calls and sms's. It means the agents at loans department are not doing their job well. They don't check information on their system before sending threatening sms's and calling. When I call the department to close the account and send me settlement letter, am told it will take 3 days and am still waiting. But on the other side they threatened me. Now again they want proof of payment, which I can't produce, because I made a transfer from my current account to loan account. I submitted proof of transfer transaction from current account to them. It's the same bank, why am I struggling with them to sort it out.

settlement lement ement