Hello Vivek,
Thanks for your question.
You will need to contact billing support here:
https://azure.microsoft.com/en-us/support/create-ticket. In the link you need to ensure you are selecting a billing type of ticket. This service is completely free and they will assist you in identifying why or assessing the situation..
In the meantime, I would recommend we find why the costs came about and plug that gap first of all. To review which resources are causing billing, see steps here: https://learn.microsoft.com/en-us/azure/cost-management-billing/understand/review-individual-bill?source=recommendations
Once these are identified they can be removed while you wait for the support to be provided by the billing team
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola