Lost Phone Number and Backup Codes

Hi, I recently used a voucher for Razer Gold Coins, but I cannot use them because this account was linked to an old number that I lost and I cannot receive OTP’s anymore. I don’t have the backup codes as well. I need help in changing the 2FA of this account. I sent a ticket 2 days ago regarding this concern and there has been no response can anyone help me please? Thank you.