I wouldn't freak out yet. I would just keep your eye on it:).

How wrinkly do you let it get before you water?

Yes, what does the wrinkles mean as well?

Could be dehydrated. They're dormant right now so I wouldn't water till it flowers or give it a drink late Aug.

You could give it s drink now, but just remember they're not actively growing. Maybe give a drink and leave be till the end of August.

Lithops can be picky so doing a little research will help you and your new little purchase out a lot.

Here's a little Info:) that I think is helpful:).