Who do I contact?

I purchased this app and enjoyed it a great deal as
well as the taeguk app. Now neither are available? I reset my phone and went to add them again and cant? That is ridiculous! Why create an app and have people purchase the videos and then delete it? Disgusted.

saejinkwan about Kukkiwon Taekwondo Poomsae : Blackbelt's Patterns, v1.0