How do I prove legitimacy of ownership to them, when I've showed essentially everything?

My ping for Mumbai and Singapore was spiking so I submitted a ticket to Riot. So, here comes the issue, I placed in the ticket that my friend was the creator of the account, as he guided me through creating it as I did not know how to at the time. Technically, he was the creator of the account, however he never played on the account nor did anything on the account. My friend never used the account, but it seems we gave off the message of account sharing. I've spent quite a large sum of money on it already, and I really don't want to lose it. (I just bought the SEN bundle too...) (I've emailed riot support a lot already, but they keep asking me to contact the original owner of the account, and I have no clue how to do that when I am the owner and the account was made way way back in 2021)