Furlenco — asking for illogical payment

I have paid every month rent still they are asking for more payment i have all my receipts of payment still they are not accepting and calling me every day for payment. I am also attaching the screenshot for the last month in which it is clearly shown that my credit balance is just 1/- re rest all is cleared still they are not attending and forcefully wants me to pay for the month in which i have not use their product.