I cancelled subscription to Exchange Online (Plan 1) before free trial ended but have been receiving invoices since then. How to stop this harassment??

Hi @Mohamed Anwar Sadat,

Good day to you! Welcome to Microsoft Q&A. 

I sincerely apologize for any inconvenience caused. Regarding to your description, I would recommend you resolve each issue as following: 

1. MFA Loop: 

Since the tenant has enabled MFA, but you have not set it, I would recommend calling to Data Protection team. The data protection team is the only support team to verify and reset the account. Use this link to find appropriate phone number of the DP team Global Customer Service phone numbers - Microsoft Support. Please understand that we do not have the authorities for operating on the backends. 

Depending on your country or region. For some countries, when calling the support number, although there are about 30 seconds opening as something "you can visit the link...." But you can ignore this opening and wait until the option, then "1" as a business email user, "1" again for technical help. 

For some countries, it will be an automated conversation like: First, when you call the hotline, it asks what kind of problem you are worried about. 

Answered: authenticator. 

A: What kind of product are you using? 

B: Office 365 for business.a 

A confirmation: education or company account? 

B: For companies 

A: Are you an administrator? 

B: Yes. 

A: Do you have the other admin in your organization? 

B: No. 

A: You need one.... Service request? 

The account verification process may take some time, so, please wait while they are verifying your identity in the tenant. Once succeed, please move to the next resolution for billing resolve. 

2. Create a ticket to billing team 

• Once you gain access to the tenant, sign in to Microsoft 365 admin center to create a ticket, select Support > Help and support on the left pane.  
• Describe the issue thoroughly, please include details of the billing, so that they can determine the issue. After that, please wait for the result from billing team to know if they can help cancel the subscription or not.  
• Please understand that we do not have the authorities to interfere with the result from billing team. 
• Once the created is created, please send me the ticket ID in the private message that I have initiated earlier, so that I can ensure that the ticket will be taken care of and help you with following the process. 
• Here's how to access private message: 
  • In your thread, you will see a banner regarding to ongoing private message.  
  • Click View messages.  

If you have any further questions and concerns, please let me know. Looking forward to your response. 

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