Corrections

HELP TO CORRECT NOW!Uncorrected

Text from Rebtoncton - English

Using my English in a real situation.
Hi!
I have to send a message to a ebay seller and I'm taking the opportunity to practice my English as well.
I think they'll understand me, however I'd like to know if there are mistakes in my text and how a native would say that.
Feel to give me your suggestions!
:) Message: "The ebay was showing my product as delivered, then I've opened a case.
One month after that I had not received my product yet, then you've refunded me.
Turns out I just got my item and the case is already closed, so how must I proceed to make a new payment?"

Title
- Using my English in a real situation.
  Vote now!
- ADD a NEW CORRECTION! - Title
Sentence 1
- Hi!
  Vote now!
- ADD a NEW CORRECTION! - Sentence 1
Sentence 2
- I have to send a message to a ebay seller and I'm taking the opportunity to practice my English as well.
  Vote now!
- ADD a NEW CORRECTION! - Sentence 2
Sentence 3
- I think they'll understand me, however I'd like to know if there are mistakes in my text and how a native would say that.
  Vote now!
- ADD a NEW CORRECTION! - Sentence 3
Sentence 4
- Feel to give me your suggestions!
  Vote now!
- ADD a NEW CORRECTION! - Sentence 4
Sentence 5
- :) Message: "The ebay was showing my product as delivered, then I've opened a case.
  Vote now!
- ADD a NEW CORRECTION! - Sentence 5
Sentence 6
- One month after that I had not received my product yet, then you've refunded me.
  Vote now!
- ADD a NEW CORRECTION! - Sentence 6
Sentence 7
- Turns out I just got my item and the case is already closed, so how must I proceed to make a new payment?"
  Vote now!
- ADD a NEW CORRECTION! - Sentence 7