can i change or delete a feedback that i have left if they reply and send me the right item??
Yes, you can.
Ask the seller to send you a feedback revision request.
Did you contact your seller and give them a decent chance to fix the problem prior to leaving the feedback?
You should always do that.
You have 60 days after the transaction to voice your opinion of the entire transaction.
feedback cannot be changed unless the seller can send you a feedback revision request. Sellers have very few of these to use in any 12 month period, and your seller may not have any left.