I'm looking for some advice and I'm wondering where I stand ( I apologise in advance for the length of my post)

We originally booked to take my family of 6, 2 adults 4 children to Tunisia with Thomson. Due to the recent sad events in Tunisia we had to change our holiday. Initially I was told that we would receive £100 compensation per adult and £50 per child towards our new holiday which would be £400, I was told by the customer service agent to look for a holiday of similar value and to call back. When I called back and changed our holiday to Cyprus I was informed that we would have to pay the difference of £400 for the new holiday when I asked for the compensation could go towards this customer service agent informed me that I would have to take this up with their head office and that they would be processing the refund. When I contacted the head of this department via email I was informed that we weren't entitled to this compensation because we weren't to going on selected dates or from the selected airports. Unfortunately at the time of transferring our holiday I wasn't informed of the dates for the airports that would entitle us to the compensation. And we weren't offered travel insurance either. I didn't except their first email and I responded because didn't take another look at it as we had been told on numerous occasions that we would be given a refund.

Unfortunately our disappointment didn't end there, we were due to travel on Saturday, 11th July on Friday 10th July my son was admitted to great Ormond Street hospital with suspected leukaemia and we were told that we would not be able to travel as he was far ill and that we would have to transfer our holiday to a different date however when we contacted Thompson to discuss this we were told that we would have to cancel our holiday and lose the £4000 that we'd paid. I understand that the holiday companies have terms and conditions about cancelling your holiday but this was an exceptional circumstance we couldn't have forseen this happening, this was the first holiday abroad my family and we have saved for such long time.

Great Ormond Street Hospital kindly wrote a letter to Thompson to ask them whether they would be able to change our holiday to a different date or give as a refund due to the extreme circumstances that made us cancel my booking, unfortunately they said no. And to make matters worse I received an email from Thompson regards to the compensation for the Tunisian to Cyprus transfer in this email they informed me that they were still unable to refund the money however they hoped we had a fantastic time in Cyprus. If they had actually looked into our booking they would have seen that we were unable to travel.

I really doubt that I have a leg to stand on that I've thought ask to see if anyone could advise me

Many thanks for reading my long post