I eventually got it sorted without court action, but you pursue legal action if you are getting nowhere. First though, you should create a timeline. You complaint is a bit confusing, so I would take out a lot of the extraneous stuff and put together a clear timeline. It should state
When you booked the trip
Who you booked through
How you paid and who you paid it to
Which airlines were on the original itinerary
What happened, when
What communications took place and what you asked for
What you had to pay out in extra costs
What compensation you are seeking
In general, I would state that if you booked your tour via a travel agency, they in the first instance would be the people you would look to for redress. I am not sure what jurisdiction you are in. I am in England, so the rules are slightly different. However, I would imagine your claim would be under a small claims procedure. If you are in Boston (which I think may be the case given your final destination) you can get advice from here.
http://www.mass.gov/?pageID=ocatermi...ourt&csid=Eoca