They found her because her corpse started decomposing and it smelled bad. If that hadn't happened due to better ventilation or whatever, it would have been longer. It's pretty disturbing either way.
And that's setting aside that you'd measure her hours dead in "business days" and excuse the company for it? Didn't you feel gross including that in a sentence about someone? Her body wasn't being mailed out for shipping. It was decomposing on the office floor, on Friday, Saturday, Sunday, Monday, and Tuesday. WellsFargo is indeed open on Saturdays for partial services, and they have security every day in their buildings. That it wasn't "full business days," is some kind of Corporate Erin speech. "Business days" are for communicating a timeline on goods, they are not for excusing company negligence with DEAD PEOPLE.