SH: WhatsApp Chat & Marketing

the app says its free, they dont show charges anywhere, after using it for some time, my shopify bill shows a huge bill of $140 just for this app. I spoke with developer of this app, even they wont help me to solve this. I wont use this app ever again due to misrepresentation. they say its free but then you are charged a very huge amount of bill.

Update, they solved the issue for me and now i am satisfied with the customer service.