Indian Bank — refund money back

Refund of Rs. 200/- has been made by Amazon on 10th of may 2019 regarding a product (Order number is[protected]. The Authorization Code (Refund Reference Number) of the transaction is[protected]. But the refund has not been received yet. Bank is saying no amount has been received by them. I've talked to them again and again but no response is coming. So I need to file a"charge dispute" on them to get the full details. I need bank to resolve this issue as soon as possible or I'm gonna take some legal action.