I wasn't notified about the price of the DDOS Protection service

Question

Hello,

I had a Azure Students Subscription and was building a project on it. I kept my prices as low as possible to be able to run the app for as long as I can for free. But while I was trying to setup a private connection between my MongoDB atlas and Azure App Service it asked me if I wanted DDOS protection and there wasn't any price information there it just said if I wan't to have it or not. So like anyone would I said yes I do want to be protected, why not (I'm new to Azure)? I setup everything and slept today I got an email saying that my students plan is over. I first thought there was like a time limit or something and wanted to check my cost analysis so I can understand how much I will need to pay from my pocket. When I looked there it said no-ddos for over 100$. How could I have known the price of such a thing if it wasn't written anywhere. Normally it shows a cost of the products I'm setting up in the review tab but while creating this private connection stuff there was no price info written there so I assumed it was free. Now I lost my students subscription and there is no option for me to open a support ticket for a refund since there was no billing that was made. I just want my students subscription back and continue from where I was left.

Please help me with what I should do, thanks.