PIF letter request

Can anyone help me out there. I have proof that I paid off an old Pay Day Loan and can't get the company to send me a Paid In Full letter for my records. It is going on two months now and they keep messing with me. When I call, the manager isn't available or he tells me he sent it out. I have emailed him multiple times, called multiple times, etc. Still no PAID IN FULL Letter with Zero Balance. Any suggestions? I need this for credit reporting purposes for possible mortgage loan.

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