Your Tollgate Pro subscription lives with Apple, not with us. That means managing it works exactly like every other App Store subscription you have, and no cancellation email to us is ever needed (or possible, we literally cannot cancel it for you).
There you can switch between monthly and yearly, or cancel. Cancelling stops the next renewal. Pro stays active until the end of the period you already paid for, then the app returns to the free tier gracefully.
If you are inside a free trial and cancel, you keep Pro until the trial’s end date and are never charged. Apple sends its own reminder before a trial converts to paid, and the exact renewal date is listed on the same Subscriptions page.
Looking for money back on a charge that already happened? That is Apple’s refund process.