Michelle Owenby Design review for Mailchimp Email SMS Marketing

This app worked for me as the new Mailchimp integration however, my audience count doubled on the day I installed it. There are no duplicate contacts but the counts are doubled and the analytics for install day show a doubling. What's going on? I hope my audience isn't being hit with double emails. Can someone from support respond? Additionally, can't find a way to communicate with ShopSync support. I appreciate the explanation of what went wrong. It would be very helpful if you could tell me how to correct the issue.