Using the preferred support option depending on the issue you are facing is the best way to start have Microsoft support. You can go to your portal and create a support ticket. Go to http://portal.office.com and in the Support section, click on the New service request option:
You can read more at https://support.office.com/en-us/article/contact-support-for-business-products-admin-help-32a17ca7-6fa0-4870-8a8d-e25ba4ccfd4b.
Let's write something like Skype for business contacts as shown in the following screenshot:
Click on the Get help button.
We can see that we have a service incident that is related to the phrase that we have written. You can check the details of the issue by clicking on the View details link:
You can click on the View solutions section to look at the possible solutions to your problem.
If you click on Let us call you section, a Confirm your contact number option is shown. You can also attach five files containing up to 5 MB of data on the support case. In order to get the call, you should click on the Call me button:
