You should've known that everything but ranks and titles (and maybe even more), are temporary items you get to make your island better, get more items, etc. Everyone has lost their items they bought in the store before the reset, only their ranks and titles remain.
Giving it only back to you would be unfair because other players may have bought mcmmo too but didn't get it back. I recommend accepting the way it is right now, if you don't want to, make a
Webstore/donation support ticket.