Very bad a scam like app

I have already bought the pro app , it stopped working suddenly so I delete it from the phone and re install it again trying to make it work , however it worked but the features that I already have purchased dont work any more, I tried to make re store but it failed and the owner want me to re buy the features again . What a bad deal, by the way this should be monitored by Apple Store team to deal with it , its a crime

Free violinist about Guitar Master - Tuner and Chords Toolkit