Hello Emjaynex,
After reviewing your post, it sounds like you have two step verification setup, and it is sending the code to a different device. I would recommend that you read these articles, they may be helpful in troubleshooting your issue.
If you can't sign in with two-step verification using your Apple ID - Apple Support
As long as you still have your Recovery Key and remember your Apple ID password, you can sign in and add a new trusted device to your account. You can also remove any devices you may have lost, sold, or given away.
- Go to My Apple ID, select Manage your Apple ID, and sign in.
- On the Verify Your Identity screen, select "Unable to receive messages at any of your devices?"
- In the pop-up window, enter your Recovery Key.
- Then, under Edit your Apple ID, select Password and Security > Trusted devices > Manage.
- Remove the device you no longer wish to use to verify your identity.
- Either verify another device already listed, or select Set up Find My iPhone to add a new trusted device to your list.
Apple ID: About two-step verification and SMS - Apple Support
Add or remove an SMS-capable number from your account:
- Go to My Apple ID.
- Select Manage your Apple ID and sign in.
- Select Password and Security.
- In the Trusted Devices section, select Manage.
- To add a number, select Add an SMS-capable phone number.
- To remove a number, select Remove next to the verified phone number associated with your Apple ID.
Thanks for using Apple Support Communities.
Have a nice day
