Flipkart - Product cancellation

On **/*/**** I have ordered a Google home mini smart speaker which is worth rs ****/-. I have got a voucher from Google and due to this I just have to pay rs ***/- for the said smart speaker. During the order process there were two products in my cart and I paid for the both. But just after the payment flipkart cancelled my Google smart speaker order and only placed the other order. I called the customer service and they told me that I seller doesn't have sufficient stock so he cancelled the order. I just said okay if this is true then why he hasn't removed the listing yet. It is still in stock. If he has lack of stock he should first pur it to out of stock. After this I post this whole incident on my Twitter and then one of there social media executive talked with me and told me that there was some technical issues due to which your order got cancelled. I was like what??? One is making out of stock excuse and one is saying there was technical issue. I asked her I have used a Google voucher for the purchase will they refund it to me and allow me to use it again. She said "No" you can use it only once. And can't be used again. I said then what kind of solution I will get. She said this won't be happened again and place a fresh order amounting to rs ****/-. I said why should I pay ****/- instead of ***/- this is huge loss for me. She said we can't do anything in this matter and refused all my proposals. Kindly think twice before purchasing from flipkart. Please someone help me in this issue. I have all the proofs of telephonic conversation and want to file a complaint against them in consumer forum. I'm really frustrated with their service.