I am facing same issue even though my bank and ZebPay bank is the same - HDFC Bank.
I made an IMPS (instant) transfer of Rs. 50,000 from a bank account which was not my registered account (by mistake) so the transfer was rejected. Now they say it will take up to 7 working days to refund my money. This is a little much, considering IMPS is INSTANT!
Just an update: Today being the 7th day, I was waiting patiently for refund to arrive, and even checking my ZebPay support website for an update. Sure enough an update came, but not in the form of a refund, rather a fresh automated email saying my refund was being processed and could take upto 7 working days from today.
i picked up the phone, 20 mins and 2 dummies later, I got a supervisor on the line, who was just as dumb. He only seemed to understand me when I said that if my refund was not credited by 5pm (Wed), they would be receiving a letter from my attorney. He said they would get back to me. I waited all day. At 4:55pm I received an SMS from my bank saying my account was credited Rs. 49,990. No "getting back" happened from ZebPay's side.
After holding onto my money for 7 days, ZebPay stole Rs. 10. IMPS transfers are free (and would like to once again mention that ZebPay and me share the same banker - HDFC Bank, so technically it is a transfer within the same bank, which is again - free!).
Shame on you ZebPay.