How can you guarantee that you will get a PIF letter from them?

Send them a letter BEFORE you pay them off, make them sign off on it. In the letter write up an agreement they will accept $$xxxxxx amount of dollars as the paid in full amount. Then you can send them a money order via USPS and write on the money order (Pain in full), keep the receipt in case they decide to go back on their word. The problem with these illegal companies is, they aren't trustworthy, and 9 times out of 10 they will continue to debit your account even AFTER they have been paid in full. These unlicensed lenders want your money, they do NOT care how they get it!

This is why when communicating with a PDL company it is suggested you keep all communication to US Postal Mail or emials. This way you have a paper trail to fall back on.

I personally got 9 PIFs from my PDLs in form of written consent or email. I proposed a payoff offer to them and they accepted. When everything was paid I requested my PIF as mentioned in my proposal letter. It was sent to me right away and I filed it for my records. All PDLs do not give you PIFs, this can be the companies who try and be super evasive because they are SUPER ILLEGAL, but for the most part they do.
Best of Luck! :D