I would write and set out case against Titan and give them 14 days to compensate and refund holiday cost then go straight to Small Claims Court which is quite quick and easy to use. Under EU Regs you are definitely due to compensation for cancelled flight and, as you point out the holiday booked bore no relation to what you were offerred. It is quite unacceptable to treat senior citizens in this way and no judge would expect them to cope with this sort of unplanned journey. I have had a similar experience and won my case in Small Claims. Go to Holiday watchdog for template letters and advice. Good luck!