Hi,
For the billing and usage query I will suggest you to raise a case with Microsoft so it can be dealt with accordingly and review the resource that were in use, as you have already deleted the resources they can consider provding some discount on the account but no gurantee . You can always stop and dealloacte resources if you are not using it and good to check always the running resources at the end of day so no charges are applied.
create-ticket
Hope this helps.
JS
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