You're playing the game using modded version of APK, of course You'll get banned sooner or later. Always have this in mind.
Just try to avoid places and events where people can report You or the group You're playing with and You should be good. (No promises tho).
More Likely You just happened to be in group events without anyone reporting someone from this group. All about luck.
My previous game got banned on Year 6 chapter 34 (Edit: and I bought here 2 packs with outfits) I think, just because someone reported my group in full marks.
Now, I'm not...
Uninstall the game from Your phone,
Install it again,
Create new character,
Play tutorial,
Open Settings to link Your account,
Link it to Facebook,
When asked about earlier save just click to use the new one.
It's not that hard 😉