They are dishonest

I'm so disappointed with service from Easton-Berry Collection. One of my account was handed over to them so I've decided to make an arrangement with them to settle the outstanding. after final payment I've called them to request a paid-up letter and I was told to request it via email and it will be issued after 7 or 21 working days, now its been 2 month nothing was send. yesterday i tried following-up I was told my letter was send and there's nothing in my email. the lady who was assisting to resend but never did. I'm highly disappointed and being treated unfairly