I was late.

If I could sleep as much as I want, I would sleep whole day.

I was late for work. Sometimes I can’t wake up in the morning.
Of course, I set 2 alarm clocks, and my phone alarm. I don’t know why, but sometimes I can't hear anything.
So, I bought a powerful alarm clock. It’s called “Super RAIDEN”.
I can choose three alarm levels, MIN, MID, and SUPER.
In fact, the alarm is so noisy that the 'SUPER' alarm level almost sounds as loud as a helicopter, according to the manufacturer's website.
From now on, I will never be late. I hope.

(Or you could say, 'Hopefully, I'll never be late again', which sounds a bit more natural and fluid.)

I was late.

If I could sleep as much as I want, I would sleep the whole day.

I was late for work. Sometimes I can’t wake up in the morning.
Of course, I set 2 alarm clocks and my phone alarm. I don’t know why, but I sometimes can’t hear anything.
So, I bought a powerful alarm clock. It’s called “Super RAIDEN”.
I can choose three alarm levels: MIN,MID,and SUPER.
Actually, the alarm is so noisy. According to the manufacturer's website, the SUPER alarm level sounds almost like a helicopter sound. 
From now on, I will be never late. I hope.

Very good. If you have any questions about my corrections, please don't hesitate to ask.

Best,

Wenwei