YOU SAID:

I’m sorry about the late response you sent to the wrong number but you didn’t mean to call him I just don’t understand why

INTO JAPANESE

私は間違った番号に送信する遅れている応答については申し訳ありませんが、理由を理解していない私はちょうど彼に電話するつもりでした。

BACK INTO ENGLISH

I am so sorry about the delayed response that is sent to the wrong number, but do not understand why I was going to just to call him.