> they told us we'd have to bring in our own laptops.

Ask if there are any exceptions-- perhaps they have an old, un-used loaner laptop lying around. Also, this wasn't a stated pre-condition of your internship. Do they typically change terms with partners after an agreement has been made?

I once had a summer job working for a landscaper. They never asked me to bring my own lawnmower and rake. Normally, it's the employers responsibility to provide basic work tools.