If you didn't get the package and facilities you booked and the rep didn't help, keep complaining.
However:
Keep the complaints concise and state what you want out of the complaint.
I found with my complaints to First Choice that if I added a side comment about a minor matter, they would jump on that and totally ignore the rest of the letter, in their minds closing the incident. Until of course I reopened it. Then they would try that with the next one etc.
Persevere until you have to threaten legal action, or you could just contact Ros and see where you stand anyway. In your circumstances it may be the best option.
As I understand the system, you will not get anything back on the grounds that the price reduced to half of the price you paid, that is down to bad timing and nasty tour operators. You will also not get anything for not getting little extras that one would have thought included unless they are in the contract.
You will have to concentrate on claiming compensation for not getting the package/facilities you were due and so will have to clearly establish the facts (dig out the old brochures). I may be wrong , which is why contacting Ros is the best idea.
You have not stated the hotel and country, which would be quite useful as my daughter is looking at this sort of thing for next year.