Used carotone lightening cream on my armpits and it made discoloration worse

Hi! I decided to try out carotone lightening cream because I heard it could help with under arm hyperpigmentation. I used it ONCE and it turned the skin all around my armpit red and the discoloration has gotten worse. This was a week ago, I figured if it was irritation it would be gone by now but it’s showing no signs of going away. Does anyone have any ideas on what to do?