Which do I apply for?

Two jobs, one business.

Position 1: Call center Rep--requires a HS degree
Postition 2: Call center Sup--requires a BA or BS and experience as a team leader.

My experience: 6 months in cold calling, 3 months experience as team leader for a student fundraiser

Do I built up the experience as a team leader, knowing I'm going against people who have much more experience or do I just apply for the position of the rep?

Gah--I really can't write today. I'm sorry--laptops don't mesh well with me!

You have a degree in communications, go ahead to apply for the call center supervisor job. Do not give up your 4 years education! Even you did not have a paying job before, your education, knowledge make you qualified for the supervisor position.

Maybe go for the higher. Odds are if they find someone that more matches their cookie cutter request, but they are still impressed with you, they will offer you a rep job. Or you could just go rep and be a good worker and eventually get promoted. Job ads put out an idealized list. They may not be able to find someone 'perfect.' So if you think it's work you could do well, it wouldn't hurt to apply.

Do you have the BA/BS degree? If yes, then obviously apply for the Supervisors position.

If no, stick to the rep, you don't have enough experience as a team leader to overcome the lack of degree.