The phone number of Windows Defender Customer Service is not available. There is no direct contact number to the Windows Defender customer service over the phone however Microsoft offer a virtual agent instant chat for your queries. Explain the issue you are facing with the Windows Defender virtual agent customer service and it will redirect you with links to solved problem that you are facing with. If the virtual agent was not helpful, you can visit Microsoft forum page and find the answer to your issue or start a new discussion in the forum page.
TheCustomerServiceNumber » Windows Defender Customer Service