PreOrder App+Partial Payment K

(Update)
After emailing shopify and Dan from the app development team, they found a bug with the billing issue and I was refunded fully few days later. Dan is kind enough to offer me free use of their app going forward, so overall every thing is settled, hence revising my rating for the app.

(Previous review)
Sudden very high charges. despite getting less than 5 no pre orders. I have orders that sync from shopee, lazada and own online orders together at shopify. But there was a SGD 68 charge, this is ridiculous.