No Paid Up Letter Received from UDU as promised via phone call - 1.5weeks now

Seems as if this forum/website is my last hope of getting a response from the institution this is directed at.

I have requested a paid up letter for my loan with that I had with UDU (smart online loans). On my first request, I had received a settlement letter valid until the 28th March and made payment accordingly, but since the first request wasn't answered 2 days later, I made another request and received the second letter 2 days after the first with a higher settlement amount. Thereafter a debit was taken off my bank account after the loan account was settled, the debit was reversed after a notification email from myself but the settlement letter is yet to be received due the 'outstanding balance' the last statement showed.

Payment was made against the settlement letter that was still valid and my only request is the paid up letter.