Hey, @varunavikhari Welcome to Spotify Community and thanks for reaching out here!
First of all, I'd like to ask for some information to better understand what is happening here. So let's go! Could you access your account overview page and check what is the current Premium plan displayed there? Also, I'd like to know if you were already charged for the Premium Duo plan. You can also double-check your receipts page, for more information.
Keep me posted and stay awesome!
Help others find this answer and click "Accept as Solution".
If you appreciate my answer, maybe give me a Like.