That is indeed the charge from March's update (version 1.03), published on March 31st. And since you removed your pledge before we posted April's charging post, you didn't get version 1.04.
Each charge from this game's updates is included in your next bill. So patrons who got April's update were charged on May's bill. As I said, we don't charge upfront.
If you have more questions, just let me know.