Hello Gbenga,
Thanks for your question.
Please create a support request to Azure billing and subscription management team and they will help you enabling the account and making the payments. https://azure.microsoft.com/en-us/support/create-ticket
Here is the link of how to- https://docs.microsoft.com/en-us/azure/azure-portal/supportability/how-to-create-azure-support-request to create support case.
Azure Billing and Subscription Management support is included in the Basic Support Plan without any charge.
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola