Jiomart — Fraud regarding money

In 2021 Jiomart introduced a feature called cashback where they give some percentage of our order value back in the form of cashback, Things started becoming fishy when they were showing me products to order and after i ordered it then they removed it from my order while processing it and returned that refund amount in form of cashback instead of returning it into jiowallet which is also integrated inside Jiomart since its launch, i thought maybe it is possible because the data on their website isn't update realtime so items can go out of stock after i placed order since they take items from their Reliance fresh outlets, but it didn't happened once it kept on repeating, i ordered 30 to 40 items and out of that 10 to 15 items were regularly being removed when it was time to ship my order, and they continued to refund non deliverable items money in cashback, Not in my paytm account which was the payment method i used nor they let me deduct the amount from cash when same thing happened in cash of delivery orders, so now the situation was i was paying full amount online and full cash in real life while i was getting less products and i was couldn't do anything about it because i was getting remaining amount in cashback so my money was safe in that bank sort of feature. Now what happened is they removed cashback feature and i had around 430 rupees out of which 400 was my real money which i paid fully in cash and online but got refund in jiomart not in paytm, I sent email to jiomart reps about it and they are now telling lie that it was just a maha cashback offer when in reality it was a feature, If it was a offer then why no customer was ever shown date of its removal at all times? The only way to withdraw cashback balance was to use it as discount on my next order but they kept on removing items and refunding the same discounted value back into cashback. This is unethical business practice where a person money is forcefully being stored on their cashback feature and then they suddenly removed it at their own wish with no transparency at all.