I have contacted the Microsoft support about this issue, but it is still not solved. Hence, this discussion. Their last response was:
Thanks for your patience with Azure support while we investigated your service interruption. It looks like you’ve exceeded the daily purchase limit for resellers.
Please wait 24 hours before attempting another purchase. Security checks like these are kept in place to protect the quality and integrity of the Azure service.
Microsoft Customer Service and Support
Tried it again for days now and even using a new Microsoft account but to no avail. For some reason, their Azure have different payment method module than Microsoft 365. Remember that my credit card was successfully used in Microsoft 365.