I have a better suggestion. Do not take advice from roslinpl, IMO.
No, you didn't.
"I am sorry to hear of these transactions that you did not initiate. I would also highly advise against ever using this compromised wallet again, as someone else clearly has the private keys in it. Changing your password & adding 2FA won't matter if the user has control of the private keys for that address. You need to never use that address or other addresses in that wallet again, set up a new wallet with new passwords & addresses, and enable Google Authenticator with that."
You imported someone else's private key, and then wrote to support asking about seeing someone else's transactions. What did you expect them to say?
They gave the best advice they could under the circumstances.
Crazy.
No, what is crazy is that you imported someone else's private key, and then panicked that you could see their transactions. Then you stole some money from them.
Another address with same private key that someone else have was added to my wallet without me.
No. It was you who intentionally imported someone else's private key.
You said it.