Hi Dan,
Please follow instructions in article below to elevate access:
Elevate access for a Global Administrator
Once you have elevated access, sign out and sign-in again for the change to take effect.
Next please navigate to list of subscriptions in portal:
https://portal.azure.com/#view/Microsoft_Azure_Billing/SubscriptionsBladeV2
Click on your subscription, then on left click Access control (IAM) blade.
Click Add -- Add role assignment, next click Privileged administrator roles tab, select Owner, click Next, click Select members, search for and Select your account, click Next, on Conditions tab select Allow user to assign all roles (highly privileged), click Review + assign, Review + assign.
After adding Owner role assignment, please sign out and back in for the change to take effect.
Now check if you have ability to create support requests and access resources in subscription.
After you are finished please remember to toggle the elevated access back to off.
If something is unclear or you have a question please add a comment below.
Please click Accept Answer and upvote if the above was helpful.
Thanks.
-TP