Everything to do with money lives under Settings → Billing.

Past invoices are listed under Billing, and each can be opened and downloaded. They go by email to the workspace owner, so if a colleague handles expenses, forward them or make sure the right person has access.
Company name, address and tax details appear on the invoice, so set them before the first one is issued rather than asking for a reissue afterwards.
Usually the card, not the account. Check:
Update the payment method under Billing and retry.
Confirmation usually arrives in moments, but occasionally lags. If a charge left your account and the plan did not change:
The invoice number or the date and amount, what you expected, and what happened. Never send full card details — we do not need them and cannot use them.
Handled by a person, always. File a ticket and it goes to someone who can act on it.
Related: Plans & billing explained · Contact support