Hi @Pranav Sharma,
Welcome to Microsoft Q&A Platform. Thank you for reaching out & hope you are doing well.
We understand that you are unable to delete a public IP address and a virtual network subnet because they are linked with "appgwLoadBalancer," a resource that you don't have access to, and you don't have a support plan to raise a support ticket.
To troubleshoot further, we will need a specialized 1:1 session, where a support engineer can have a screen share session and help you resolve your issue. As you don't have a support plan, in case you need help with a one-time free technical support, please do let us know.
We will try and help you get a one-time free technical support.
P.S: We will be able to provide you one-time support if and only if your subscription is not managed by a CSP.
Regards,
Sai Prasanna.