Hi Tony Tang, I want to help you with this question.
It seems that you unintended ordered the Basic Azure Support Plan:
https://azure.microsoft.com/en-us/support/plans
The support plan basic cost 29$.
This can happen very quickly when creating a subscription.
It is best to disable the support plan in the subscription if you do not need it.
Search for “Help + Support” in the Azure portal. From the Health + Support Option, Navigate to “Support Plans“. You should see the activated support plan. Here you can also cancel the subscription for the support plan.
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