You have used my photo without my permission. Could you please delete it asap?
I see my photo on your website but I never gave my consent for this. Could you please take it down as soon as possible?
この場合、次のように言うと良いでしょう。
ーYou have used my photo without my permission. Could you please delete it asap?
「私の許可なく私の写真を使っているので、すぐに削除してもらえますか?」
to use someone's photo without one's permission で「許可なく人の写真を使う」
to delete で「削除する」
ーI see my photo on your website but I never gave my consent for this. Could you please take it down right away?
「あなたのサイト上に私の写真があるが(載せることを)承諾していないので、すぐに削除してくれませんか?」
to give one's consent「承諾する」
take ... down「…を消す・削除する」
ご参考まで!