Your subscription can be deactivated for different reasons. To reactivate, see:
https://learn.microsoft.com/en-us/azure/cost-management-billing/manage/subscription-disabled
Also you can get support from the billing team if the above cant help you fix:
https://azure.microsoft.com/en-us/support/create-ticket
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola