Are you sure that you deleted all resources before you upgraded your account to PAYG?
Please refer to this link for more details: [https://learn.microsoft.com/en-us/azure/cost-management-billing/manage/avoid-charges-free-account
I'm new to Azure; I used the free trial subscription to create some App services, but it was about to expire, so I deleted all of them and upgraded the subscription plan to Pay-As-You-Go with basic mode.
However, I can see that it charged some amount on the Cost. Could someone please guide
why this is the case?