Change your e-mail address
Write to support@ktkarena.com from your account's current e-mail address, and give in your message the new address you want to use.
Your address is used to sign in (e-mailed code) and to receive confirmation codes, like the one for deleting your account.
You no longer have access to your current address
Write to support@ktkarena.com anyway, from another address, explaining your situation.
What about the phone number?
Your account doesn't have one: you sign in with your e-mail address (code or password) or with Google. So there's no number to change.