I understand that patreon works like this, maybe I was misreading or it was not understood what I wanted to say (sorry, English is not my mother language).Please lookup the meaning of patronage. This is what Patreon offers. It isn't a platform from where you order "updates" or complete games.
If you think your money is wasted withdraw your support and move on. No one force you to continue to support someone on petreon neither did you sign a contract with Patreon nor with the artist.
Therefore a punishment system isn't needed, because you have full control about the amount and duration of your support.
My tip: Make a "donation" as soon as an update is available and wait for next update and "donate" again. Or wait a full year and get a bigger update for the same "donation".
I mean, if you, as a creator, are committing yourself to your sponsors on certain dates, you are obliged to meet them, or if you do not suffer penalties from there, why give a departure date for your product and then delay it 4 times? is to be deceiving your sponsors, (you could also say that it is a fraud), since you are not complying and what it seems is that you give one excuse after another for your delays so that people continue to contribute money.