BIG TIME CHEATER COCK

hello friends
i m a frequent buyer on these e-commerce sites. Even i have purchased so many products on snapdeal in past. They all are good and in grate pricing. But now this site start cheating their customer in the name of promotional offers……..
Recently, in the month of july,2015 they offered a promotional offer of 10% cash back on using SBI debit card/credit card on purchases above rs 6000. I have placed an order no 5885752187 (for 5 itams namely memory card, ac stabilizer, wall fan, ladies purse and car mates), which cost me rs 6070 and as per the promotion offer i have used my valid state bank debit card to pay the amount. They conformed the order. But later on after 2 days when they have dispatched other 4 items of the order, they canceled one item of the least amount (rs301) at their own and send me the refund (while that item is still available for purchase on their website at that time of cancelation).—— [this was purposefully done to decrease the total purchased amount just below 6000}
When my pay back amount of rs 607 is not credited back in my account I called at their customer care and ask regarding this so they replied me that I should wait for some time and it will be automatically credited back to my account. But noting happen even after 20 days………….. then I again called in customer care- and they finally told me that due to that cancelation of one product my total purchase amount reduces just below rs6000 (that is rs5800)
So that refund was not credited back to me. Now when I asked them who is at fault in this as I have not canceled that item. Then they have no answer for this and said that they will send my complaint to appropriate authority………….but no result – no communication from their side. Then I again and again complained on their site and customer care with my complaint number is 03543341. But no answer from their side { they have purposefully canceled one product of least amount i.e rs 300 to prevent paying back of rs 607 ). They are the biggest cheater online…………beware of their promotional offers…….. they just wanted to fraud you. I have mentioned each and every thing in detail with their reference number……..HOPE my bad experience will help you all in purchasing things online { one important thing to mention——I haven’t experienced these type of things with flipkart and amason—— their product are slightly costlier but their services and products are excellient