Have you had the experience of was acting on a sudden impluse to do something and regretted it later.I had one.Once I went shopping by myself. I saw a beautiful bag in the window of an expensive shop and I liked it very much.I went in and looked at it for a moment, but nobody came to greet me.
  I tried to put it on when a sarcastic voice spoke up :' the bag is very expensive, if you can not afford it, please don't  ask to see it.' 
  To my surprise, I saw a  middle-age woman who was a large,unsmiling lady in a tight black dress coming down from the second floor of the shop. I was very astonised at what she had said.
  'How do you know I can not afford it?' I said angrily.
  The woman was busy cleaning her shop and did not pay any attention to me at all.' So do you want to buy it?' she glanced at me scornfully and asked drily.
  I regretted answering in the way I did, but I said:'excuse my interrupting you. I hate to interrupt a woman when she is busy working, but would you mind wraping it up for me?'
  'Sure, I'm very gald to do that.' she answered with a smile.Meanwhile, she quickly wrapt and handed it to me. 'One thousand yuan,please.'
  'It is very expensive.' I said to myself.  I paid the money reluctantlly and took it out of the shop. Even if I liked it,I did not have any clothes to match it.There is a saying is that impulse is the devil. And that day the devil provided me a very expensive lesson.

Impulse is the devil

Did you ever have an experience where you acted on a sudden impluse to do something and regretted it later? I have one.  (<em>Because you're telling a story about something that happened to you, I put your verbs here in the past tense. You also need the "it" to refer to the previous action</em>.)

Once, I went shopping by myself. I saw a beautiful bag in the window of an expensive shop and I liked it very much. I went in and looked at it for a moment, but nobody come to greet me.
I tried it on when a sarcastic voice above me said:' the bag is very expensive, if you can not afford it, please don't ask to see it.'  (<em>above me instead of "up</em>")
To my surprise, I saw a middle-aged woman who was a large,unsmiling lady in a tight black dress. She came down from the second floor of the shop. I was very astonished at what she said. (<em>past tense!</em>)
'How do you know I can not afford it?' I said angrily.
The woman was busy cleaning her shop and did not pay attention to me at all.' So do you want to buy it?' she glanced at me scornfully and asked drily.
I regretted answering in the way I did, but I said:'Excuse my interrupting you. I hate to interrupt a woman when she is busy working, but would you mind wrapping it up for me?'
'Sure, I would be very happy to do that.' she answered with smile. Meanwhile, she quickly wrapped and handed it to me. 'One thousand yuan, please.' (<em>We know she's going to wrap it up for you by  now, so the future tense works best here.</em>)
'It is very expensive.' I said to myself. I paid the money reluctantlly and took it out of the shop. Even if I liked it, I did not have any clothes to match it.There is a saying is that impulse is the devil. And that day the devil provided me a very expensive lesson.

Your writing in English is pretty good! You seem to have a good hold on the past tense. There was only one spelling error- excellent!