Airline (Air Caraibes) refuses to compensate for baggage delay - what are my options?

Context

On the 19th January 2019, I flew from ORY (Paris Orly - France) to PTP (Pointe à Pitre - French Caribbean) with Air Caraibes.

The flight got delayed (2h42 according to the company) and once we arrived at the destination, passengers were told that because the plane was not the one initially planned, pretty much none of the luggage were actually in the baggage hold, that our luggage would "probably arrive the day after in the afternoon" and that we'd have to queue to fill various papers.

After queuing for an hour (only between 1 and 3 staff members - not sure if airline or airport - were filling papers manually for all passengers of a full plane), it was eventually my turn and took this chance to ask about the procedure regarding things we'd need to buy. I was told that we'd "be obviously fully refunded for the corresponding expenses" and that'd we simply have to keep the receipts.

Issue

Ever since, I've been struggling to get the compensation for expenses (swim suits, toothbrush, toothpaste, sun screen and shower gel) by sending of loads emails and customer complaints to the airlines.

On the 12th Avril, I was eventually asked for the following documents:

• luggage report filled at the airport

• rush tags

• receipts corresponding to essentials

which I provided on the 25th April.

Then, on the 13th May, I got a replying saying that "compensation only applies to delays longer that 24 hours".

I cannot find anything related to a 24 hours delay for compensation online (here for instance).

A 24h delay seems pretty arbitrary to me as the essentials we'd need for the first 18h hours not so different from what we'd need for the first 24 hours...

Is it legal ? Is the fact that I was told otherwise (with no proof) relevant ?

What should I do ?

Additional details which only makes the story worse:

• we were delayed 2h42 then wasted one hour to fill papers but we cannot get compensation for this because compensation starts after a 3 hour delay

• because the plane was not the one initially planned, there was no multimedia system whatsoever and we were not warned beforehand - a 9 hour journey appears longer when you did not take any book or computer

• the air crew fully knew that almost no baggage where in the baggage hold but no one was told until we were at the destination

• an insufficient number of staff were handling the passengers

• in the afternoon the next day, we had no news related to our luggage despite trying to contact the airline via all possible ways (customer request, phone calls, emails, etc) - not the best way to spend the first day of holidays

• eventually, I contacted the airport which told us that our luggage were indeed ready to be picked up

• the form filled at the airport asked for the address we'd be staying at but nothing was done to deliver the bag to our hotel so that we'd have to go to the airport ourselves (more than 1 hour each way) - again not the best way to spend the first day of holidays

Even if technical incidents happen, Air Caraibes handled the situation in the worst possible way with no communication at any stage of the problem