zigzterIf you used a credit card to buy any games you can give them the last 4 digits and the name on the card IIRC.
If you used PayPal you can use transaction IDs or something.
the really weird thing is support gave me this
You and another user have provided proof of ownership that shows that either of you could be the owner of this account.
which makes no sense at all to me because there's been like 2 purchases on steam for this account, one $5 steam wallet deposit so I could get TF2 premium (which I gave a paypal screenshot of with trans ID) and csgo (which i got off g2a and have a receipt for activation)
like there is literally no proof of ownership except what i have