anyone know that Islamic home loan refinancing from coventional loan entitle for the stamp duty exemption or not ?

yes, you can. write in to your home branch and seek for interest rate revision. If u got the other bank refinance offer letter, lagi best, the home branch usually use this to appeal with HO to the interest rate. But provided you can get offer letter before signing and get to your existing bank loan in the revision. Usually u get the offer letter when meet up with the loan agent and sign on the spot.

I did submit for request interest rate revision, but subject to your existing bank policy.

A minimal costs (few hundered) for the processing/admin fee charged you.

Successful rate depends whether you hold the new offer letter from other bank. If just submit payslip/epf , unlikely the revision rate will be approved.

I proceed to refinance with another bank (as offer letter signed), given my existing bank interest rate can adjust to same rate with new bank.