可以幫下我嗎?

樓上有幾個grammatical mistakes,我會咁寫

Dear xx,

First of all Please accept my apology as I misunderstood your instruction yesterday. (事件已發生,應該用Past Tense). I mistakenly deposited the check to the bank yesterday instead of today. Once again, sorry for any inconvenience may have caused to you.

yours faithfully

your name

Dear xx,

I misunderstand your instruction for the payment deposit, I deposited the funds to the bank yesterday instead of today. I apologize for any inconvenience cause.

yours faithfully

your name