New England Mischief review for Sesami Booking App

Shopping appointments are 60 minutes(the only way to set this up to have time to clean in between. Tried 45 minute variant but that gave us no time) and are every hour, on the hour, yet someone was able to book an appointment at 3:30, thus wiping out the 3-4 and 4-5 time slot. We have limited hours due to COVID-19 restrictions and we have now lost an appointment. I need to know how to fix this issue asap. I have submitted 2 support tickets with no response. Almost 72 hours later and still no response.