FD30 fire doors and MVHR, large gaps

[Guest questions for MVHR]

Hi, I've undertaken a full refurbishment of my home and have problems with sound travelling around too easily. All the internal doors are new and have gaps of 1-2cm at the bottom with no intumescent strips anywhere around the door or frame, and there is no certification label on the door. My architect specced FD30 fire doors which my builder fabricated and installed himself. I don't think these are FD30. My architect is now saying the doors need large gaps at the bottom to accommodate the MVHR ventilation system. 

1. Sound is travelling too easily with these big gaps - can I have flush fitting doors that reduce sound transfer whilst allowing the MVHR to function? 

2. Are these FD30 doors? They seem like FD20 now so I didn't get what I paid for. 

3. What can I do short of replacing all the doors? 

After completing the build the builder went bankrupt and setup a new company with the architect. I feel really messed around but not sure how to progress. There are other problems that the architect is blaming the builder on (poor internal acoustic insulation) and telling me I have no legal recourse now that company has closed. 

Any help much appreciated, this is a pain