Snap Fitness review: unauthorized credit card charges

Hello, my name is [removed] I am coming to you very frustrated as the owner of the Holyoke MA Snap Fitness has been engaging in back to back emails with me saying he was authorized to take an extra month of payment out even though we canceled with 30 days written notice. Myself and [removed] joined on May 29, 2018 and on May 29, 2019 (30 days before an unauthorized payment was taken out) we emailed owner [removed] saying we were canceling membership. So when another payment was taken out on June 28 th we contacted the manager of snap to ask why, despite us giving exactly 30 days notice (May 29 to June 28 is 30 days) we were charged for yet another month. She replied by saying the owner told her the last payment was for June (even though we pay the on the 29 th or so of every month for the upcoming month.) so our June payment, which should have been our last, was taken out on May 29 th. So we contacted the owner directly with proof of date we signed up, proof of cancellation email ( which he claims he didn't see but we have the time stamped sent email). He continues to reply by saying we did not cancel in time even though we followed the exact cancellation policies we were given. 30 days notice. I sent him a copy of the cancellation policy and he continues to say we didn't cancel in time. I don't know what else to do at this point because he isn't abiding by his own cancelation policies. He's saying the 30 days fell into the next billing cycle but if you don't want that to happen you would have to cancel with at least 31-32 days notice. We made sure we canceled 30 days ahead of the next billing cycle (31 if you're going by the day we were first billed when we signed up.) I'm very frustrated and am not sure what to do at this point. Help would be greatly appreciated. Thank you