if i send money to someone via apple pay and canceled the transaction, will i get that money back on my card?

Yes. See the following from Send, receive, and request money with Apple Pay - Apple Support

If you reject or cancel a payment, the money will be refunded by the next business day depending on your bank or card issuer.

Hi,

You should but it may take five to seven business days to be credited to your account.

Do you know if the person has accepted the payment yet?