بسم الله الرحمن الرحيم
(Fatwa: 80/94/M=2/1438)
You may avail the said scheme and may take 15% or 10% cash back. It is lawful as per the Shariah provided you do not involve in any interest based dealing.
Allah knows Best!
Darul Ifta,
Darul Uloom Deoband
