Natis certificate extausion!!

I would like to express my frustration regarding VW finance and how unfair they are to me as customer. I paid off my car in may/June 2024, I was asked if I would like them to sent me my Natis certificate so I can go do change if ownership but instead they offered and alternative that they can do it for me but I should pay a certain amount and use a certain ref. Which is what I did now I been asked multiple times so sent them pop in a form of pdf. Which u need to pay for at my own cost. Ot them. However my frustration is that how am I now been asked to sent pop. Over and over or in a form of pdf. While they can clearly pick up or in a second when someone has missed payment for example. But they cannot pick up that someone has paid them instead they asking for pop and giving Run arounds. It's been months since I been waiting for my certificate and till this day I did not get any call or even communication from them instead all I get is the email saying I need to sent pop. For them to assist. I really feel this is ridiculous and unfair just because I do not owe them anymore but they feel the need to keep my Natis with them, while they are they once offered the option to do change of ownership on my behalf.