I am unable to log in to my account.

I understand you're having trouble accessing your AWS account due to MFA issues with a company landline. Here are some steps you can take to resolve this situation:

1. First, try the "Sign in using alternative factors of authentication" option if it's available. This may allow you to verify your identity using other methods, such as email.

2. If that doesn't work, you'll need to contact AWS Support directly. They can assist you with deactivating the MFA device and regaining access to your account. You can reach out to AWS Support even without a support plan for account-related issues like MFA problems.

3. When contacting AWS Support, be prepared to verify your identity. They may ask for information such as the email address associated with the account, the account ID, and potentially other details to confirm you're the rightful account owner.

4. For future reference, consider using a virtual MFA device like Google Authenticator or Authy instead of a phone number. These apps generate codes without requiring a cell signal or specific phone line, which can be more convenient and flexible.

5. If you're using an IAM user account rather than the root account, you may need to contact your AWS administrator within your organization. They can help deactivate your MFA device and set up a new one.

Remember, it's crucial to have alternative authentication methods set up to prevent lockouts in situations like this. Once you regain access, consider registering multiple MFA devices or setting up emergency access keys to ensure you can always access your account.
Sources
Recover an MFA protected identity in IAM - AWS Identity and Access Management
MFA device reset for root user | AWS re:Post
issue for MFA authentication | AWS re:Post
Unable to login to root user(MFA autentication failue) | AWS re:Post

Hello.

Have you tried accessing with an alternative authentication factor by following the steps in the document below?
If you try it and it fails, you will need to contact AWS.
https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_mfa_lost-or-broken.html?icmpid=docs_iam_console#root-mfa-lost-or-broken

You might see alternative text, such as Sign in using MFA, Troubleshoot your authentication device, or Troubleshoot MFA, but the functionality is the same. If you can't use alternative authentication factors to verify your account email address and primary contact phone number, contact AWS Support to deactivate your MFA device.

I recommend that you contact AWS via the following URL:
https://support.aws.amazon.com/#/contacts/one-support?formId=mfa