Help with Bot Attack & billing

I got hit with a bot attack on my Shopify checkout and now I'm stuck with a billing mess. My active profile count spiked hard mid-cycle because of it, and even though I've already suppressed (and then deleted) the fake profiles, my bill is apparently still based on that peak number from during the attack.

It’s my first time learning about email lists, so I didn’t have double opt-in on. I did have CAPTCHA on the whole time, so this wasn't a case of me being completely careless. The automated signups were clearly bot activity, especially looking at the fact that over the past 6 months I didn’t even get as many signups as I did on the day of the bot attack. Doesn't seem right that I'll get billed for this.

Is there a way for Klaviyo to adjust my bill back to what it should've been without the bot spike? 
Anyone know what proof they'd need to actually look into this?
And is there any way to get this in front of an actual person, since my support access shows as expired?

It’s absolutely ridiculous that I randomly get bot attacked by just the right amount of bots to put me over my Klaviyo threshold, and that Klaviyo then asks you for money if you want to get this fixed.