My debit card was charged for computer equipment without my authorization

So call your bank.

There is no specific number to call except for the bank itself. Best to go into the bank and dispute the charge.

Look on your debit card. Both of mine have phone# on them. However, you might be out of luck with a Debit card. Someone must have had your PIN.
Read this too.--https://www.nolo.com/legal-encyclopedia/unauthorized-credit-debit-card-charges-29654.html