Econ is in the School of Arts and Sciences at Providence, not the business school. Providence has already admitted OP, so they see OP as a good fit.
Until OP responds to the many questions that have been asked on this thread, it doesn’t seem there is any basis to ask for more FA (mistake on forms, larger offer from peer school). In the absence of those things OP can still ask for more $, but I can’t imagine it would result in more than a couple of thousand dollars, maybe $5K max. Hopefully OP will return and let us know about affordability.