Cancel on someone three times and don’t be surprised when there’s no fourth invite.

Invitations are a cost somebody pays repeatedly. Each one is a small risk, and three cancellations give a reasonable person enough data to conclude you are not available, so they stop asking, which almost never gets announced and usually gets mistaken for them losing interest. You will not be told that you spent the credit. The invitations just quietly stop.

If you have cancelled more than once on somebody recently, be the one who proposes the next thing and pick a time you can definitely make. Keep it small enough to be safe. Then turn up, because one kept plan rebuilds more than an explanation will.