Shoppersstop.com — Account deactivation

When the account is created they do not ask for any ID proof. Now recently I noticed that there exist 2 accounts from my phone number. One of these accounts was in some other name, and I don't have any idea how it got created. So I asked them to deactivate my account but now they are asking for my Aadhar details. I don't want to share such sensitive data with them as I have 0% trust in my data security with Shopperstop. Since the mobile number is with me and I am willing to authorize and share any OTP they should close my account.