Facebook sucks at getting back to people. Worst customer service I've ever experienced.
I would post this issue to their support board:
https://www.facebook.com/business/help/community - usually you will get a quick answer from one of their online reps then through email.
Could be numerous things:
- You ran a daily budget on the campaign and didn't put an end date on it. $20 per campaign X a few campaigns X several days could be that charge.
You should be able to go into your Ads Manager and Run a Report on each campaign to see how much it spent, how many days it ran for. Can you do that and take a screen shot of it and post it here? Facebook is pretty accurate with their billing on campaigns, I've never had an issue with that. Usually its user error and they won't refund you. It sucks, but there is no manager at Facebook billing that will be contacting you.
- Maybe you had an existing balance that wasn't paid yet? If it has hit 30 days or you hit your billing limit of $250 it will charge your card and then increase your billing limit to the next threshold. Usually goes $25 charge, then $50 charge, $250 charge, and on... Or every 30 days. Since you were charged $258 it sounds more than likely you hit the billing threshold and it charged you. It doesn't charge at exactly $250 it lets you go over a few dollars or until the campaign ends. Again, check your ads manager and see what other ads you ran prior to this if any.