Quit Summer Internship?

I took a commercial banking internship with a regional sized bank (think Huntington, fifth third, etc) under the impression that I would be getting some exposure to fin statement analysis, credit, and relationship manager stuff.

I was thrown into their merchant services arm selling credit card machines. Zero finance involved, all sales and calling small businesses trying to get them to use the bank's merchant services to facilitate their card payments/transactions.

Needless to say, I cant imagine this is helpful at all for my future goals to be in traditional finance/banking. Im wondering if it makes sense to leave and just self study through wall street prep over summer with a part time job or just stay and stick it out for the brand name on my resume.

I have two contacts at the bank within the corporate side and I would hate to burn those bridges by leaving but was hoping to hear what you guys think.