Yes, I have Easyshop Platinum Visa - preferred debit card and I am still getting 1% cashback. I beleive all Easyshop Platinum card varients like classic, preferred etc are one and the same in terms of benefits.
You need to go to HDFC net banking, go to Billpay and recharge section, Add your CC biller and make payment using the debit card option. You will get cashback points in 1-3 days. Max Cashback per month 750.