Unable To Cancel My Shortmax Subscription

I am writing to report an issue with my Shortmax subscription in the United States. For about three weeks I have been trying to cancel my subscription, but the service continues to charge me despite my attempts to end it. Approximately two weeks ago, I first submitted a cancellation request to Shortmax. When I contacted customer service, I was told that there were too many requests and that they would get to my case, but since then no action has been taken and my subscription is still active and being billed. My Shortmax account identifier is: UID 197332***. I request that my Shortmax subscription be cancelled immediately and that I be refunded for the charges taken over the last three weeks while I have been trying to cancel. I also ask for written confirmation once the cancellation and refund have been completed.