Price discrepancies

I have used the free version of this app for about a month. The year subscription was $59 so I didn’t subscribe right away. I’ve enjoyed coloring daily so I decided to splurge and subscribe. The cost today is $79.99, yesterday it was $59. So I decided to download the app onto my phone instead of my iPad. When I check the subscription price on my Samsung phone it’s still $59. It doesn’t appear to recognize me at the same customer because it’s a different platform. It seems like a total scam! Why is it $20 more expensive on my iPad now? Am I being punished for not subscribing right away? If that’s the case, I will just uninstall it, there are a ton of coloring apps out there that are free or cost almost nothing.

Kerribrat about Recolor - Coloring Book, v4.1.2