Great Eastern Appliances — Issues of refund on online shopping

Address:

https://greateasterntrading.in/

I had got a cashback from great eastern for online trading on the great eastern website.
I have ordered a mixer and paid extra money from my card.
Later on, I had cancelled the order.
I waited a few days for my refund but haven't get that.
After this, I called on this number [protected] (Kolkata). the lady was so polite and humble but the line was the same on every call i.e. "we want some time", sir who handles all this thing is out of Kolkata so give us some time.

First of all, they should refund fastly as Amazon and Flipkart.
the second thing why we have to call again and again for cashback. I think it is there to send money as soon as possible.

very bad experience with online trading.