Sir,
I am an accountant. My company purchased a fixed asset. But I didn't recorded it in the books of accounts. After one year returned the fixed asset to the seller. The seller gave me credit note.

My question is can I give him debit note?
How can I give him debit note, as I have not recorded the purchase of the fixed asset??
Please give me complete step by step solutions and all the necessary entries in journals etc.. Thank you so much friends...

I don't know what you mean by give him a debit note. What has happened is an asset has been created, therefore the seller is a debtor.

If I understand you correctly you purchased an asset without paying for it therefore your original entry would have been

Dr Asset Cr Creditors.What you need to do now is Credit Asset and debit Creditors. But as you no longer have the asset these transactions cancel each other.

If you actually made a payment and didn't record it then I suggest there might be a lot more wrong with your bookkeeping than this one transaction and you need some basic instruction in accounting