One cash issue...of course

I am a Credit Union person and I just thought why bother with the all of the transfer nonsense I'll just use the card. I think pet food and gas eats up all my Spark money anyway lol.

But last Sunday I had about $39 left and wanted to just top off my gas tank before the week started. I knew I was just going to use about $25. Well, I look on the card and BP station had a $57 charge on my card!!. It quickly went away...but is that a thing? When your balance is low?