I'm sorry to hear that! You should contact Spotify Consumer Support filling this contact form.
If you receive an automated email that leads you back to the community or help pages, reply to it (even if it's from "no-reply") and one of the Spotify team members will get back to you as soon as possible.
Thanks for posting about this here in the Community!
You mention being charged despite joining a Premium for Family plan. Keep in mind that when you join a plan, all subsequent payments on your account should be made by the plan's owner/manager.
If you're still seeing charges despite joining a plan, it's possible that you have more than one account with us. We'd recommend taking a look at the steps in this Spotify Answer to locate it and cancel any subscriptions you have with these steps to avoid any further charges.