Etihad Airways review: Flight cancelled, alternatives completely ridiculous. Family of 6 - booking new tickets will cost a fortune

In February I booked flights for the end of August with Etihad. I purchased 6 tickets directly from the airline - from Bangkok to Tel Aviv via Abu Dhabi. A few days ago, I received an email telling me that my flight was cancelled and moved 2 days later. Alternatively, we can leave a day earlier. Staying an extra 2 days will cost approx $2,400 for the 6 of us. Leaving early will mean we have to rebook internal flights, lose one night in a hotel, prepaid, and lose a day of our vacation (similar value). The price of flights has more than doubled since February (paid $3000) and so even though the airline offers a refund, buying an alternative ticket with another airline will cost substantially more. Etihad will not move us to another airline.

I don't have any crazy demands and am happy to cover some of the costs from their cancellation myself, but when I suggested that I keep the Bangkok - Abu Dhabi leg and purchase new tickets for my family on another airline, they refused, saying this would require a new ticket - which would cost far more at April's prices. I don't understand why they can't be more helpful given they caused this problem. If they refund a proportion of the ticket to cover the leg we aren't flying (Abu Dhabi - Tel Aviv) I will pay the different to travel on another airline. Alternatively, they can cover the additional costs incurred.