Welcome to FlyerTalk.

Parts of your story make no sense. The only round-trip fares between Boston and Miami that are >$1000 are B fares (3 days advance purchase, but completely changeable and refundable) and Y fares (same as B, except no advance purchase requirement).

So, even if you had a 'B' ticket, you could have changes the date of your flight, as long as the return was 3 days in advance.

I think you need to provide more details if you want any advice. It sounds like either you or your secretary does indeed have a work-related problem; at this point, I'm not sure we have enough information to decide exactly the nature of the problem.