Why do I have to pay again???!!!

I payed for this app couple of years ago. I like how I can keep track of my fitness and measurements not just weight. Why do I have to pay for this app again just because there are new updates that is BS Im not paying for it again. Also Im a small person and I hate how the graphs dont show my measurements I have a 27 inch waist the graphs dont go that low. They should configure to the numbers you put in. Why should I pay for this app again so in couple more years u will want me to pay for it for a third time. No way I will look for a different app.

85wawa04 about iBody - der Fitnessmanager, v6.7.2