Unfortunately, this is not uncommon for Patreon, and it was a lot of creators' worries when the Tapastic Support Program shut down and they urged us to use Patreon.
Many patrons do pledge, download all the content they can get, and then decline before the payment goes through. I thought Patreon had changed the system to combat this, but I could be wrong (where you had to be billed first before getting access to things).
I've had a few patrons decline but I was fortunate enough that these were people that actually legitimately wanted to support me and already had been for a while - and so far they've pulled through by fixing the issue and jumping right back into pledging every time they ran into a decline issue.
Sorry to hear that you had to experience this - see what happens over the next few weeks, some of them might go through (I hope they do). You could always do what some creators do and just release a package of content every month to people who have already been billed, however this won't work as well for creators who release early strips and stuff like that (like me lol). But releasing a monthly package of content might be a way to help avoid this, though it would start to get a bit hard to manage if you got a lot of patrons.
