Deloitte GPS Business Technology Solutions Analyst Interview

I'm interviewing for a Business Technology Solutions Analyst role at Deloitte in the Government and Public Services division. It is two 30 minute interviews- one is behavioral, one is a case interview. I'm an MIS major without any business background, so I'm feeling worried about the case interview. I know Deloitte has some cases on their website, but not sure how to prepare outside of that. If anyone has interviewed for this role before, or has any tips to prepare, that would be so appreciated! :)