I'm given the run around for a Paid Up letter

The worst company I have ever dealt with. Wonga handed me over to them because I couldn't make payments on my loan. As soon as I got a job, i contacted them to make arrangements and shem they were so nice, offered to call me back and we made arrangements. Any time I would request a call back and they would call me.... Now I finished paying them off, I email them and I was told to contact Wonga. I told the lady that I've been speaking to her from the start ,so if she can please get me a paid up letter. The lady is now ignoring my emails. Warning: This people are only nice to get you to agree in signing up for arrangements. After you pay them up. They just dnt need you anymore. If possible when they hand you over to them, beg that company to hand you over to other companies except for Shapiro