Cancel ShortsWave Subscription

I am a user from the USA and I have a ShortsWave subscription that I am unable to cancel despite multiple attempts. I want my subscription to be cancelled immediately and a refund issued for the last week I was charged. I have checked my Apple subscriptions, Google Play, and Facebook, but ShortsWave does not appear in any of these places, so I cannot locate where the subscription was started or how to cancel it. The ShortsWave app itself also does not allow me to cancel the subscription from within the app. The only identifier I can see on my account is: 224b694baf6a8229. Because I could not cancel through any of the usual platforms or via the app, I sent an email to ShortsWave requesting that my subscription be cancelled and that the last week’s charge be refunded, but I have not received any response so far. I request that my ShortsWave subscription linked to the above account ID be cancelled immediately and that the last week’s charge be fully refunded, and I would like written confirmation once this has been done.