The student discount can be applied here:
There is a glitch for some people, so if you have trouble,
I suggest you contact support so they can help you
If you get an automated reply email telling you to check the help section or the community, you need to reply back to it, even if it's from a no-reply address.
Support usually replies within 24-48 hours.
You can also tweet to @SpotifyCares on Twitter for help.