Cancel Acrobat Pro DC subscription on University linked account

I signed up to Adobe services through my university email, and it says my account is linked with my University. I did this to make use of a 7 day free trial of Adove Pro DC, where I had to fill in payment details to use it but was under the assumption I could cancel before my trial ended and payments began. 

When I look at the PLANS section on my Adobe account, nothing is there, so I cannot cancel my subscription? I was wondering if this was because I set up my account through my uni email? Or maybe I cannot see the plan as its a trial? Either way I am now worried I am going to have to pay for a month of Adobe Pro DC even though I'm done using it, and was convinced it was free and I wouldnt have to pay? 

Please help, thank you