Change Phone number

I need to change my phone number on my account I reset my password because I havent accessed the account in forever because I started using a different keyboard. I went back to my razer keyboard and now I got in my razer account but my old phone number is still on there. I tried to change it but it says sent code to that number. How can I fix this? I dont have the old phone number and I never took a picture of my backup codes.