Axis Bank — unauthorized debit from my axis bank account

Address:

411038

Name : pankaj swami
Mobile : [protected]
Email : [protected]@gmail.com
I have done one transaction on 10-may-2019 on dx.com site and amount of rs. 5824.67 got deducted from my account.in my statement, it said that ecom pur/mobile phone/+/100519/00:37.
On 11-may-2019, my order got canceled and i got the refund of the same amount.
After around 4+ months, today (18-sept-2019), the amount of rs 5593.66 got deducted from my same account and when i spoke with axis customer care they said the same retailer has again deducted the above amount as this transaction wasn't successful on 10th may. I don't understand how is this even possible? How can some retailer deduct any money from my bank account without my confirmation?
Funny thing, this time in my statement retailer's info is reflected as pos/mobile pho/dt.11-may-19
I know what is the difference between ecom & pos. My question is after all these things, how axis bank authorized this transaction? And now they are saying we can't do anything from our side, please talk to retailer : (