I was charged twice. What do I do?

First check what each payment was for. A plan and a Vault are paid separately, so a plan payment and a Vault payment on the same day are two different things. Your plan's payments are under Payments on Plan & billing (click your name or picture at the top right, then My Account); a Vault's payments are on its own page (Dashboard in the top bar, the Vaults tab, then Open on the Vault). Each payment has its date, what it was for and its invoice.

If the same thing was charged twice, write to us on the Contact us page from your account's email address, choose Billing Support as the subject, and say which payments. Billing, invoices and plan changes has the rest.