Did you speak to the BA baggage rep at the airport?
Exactly the same thing happened to us last Christmas and we were boarding a Princess cruise the following day. When we told the rep we were on a cruise he noted down our entire cruise itinerary so the would be able to send the bags on to catch up with the ship. We were told to buy whatever we reasonably needed and keep the receipts which we did. We spent about $900 between the two of us when we did a mad shopping dash in Macys the following morning before boarding the ship.
The BA rep also told us to inform Guest Relations as soon as we board the ship as they are very experienced at dealing with this issue which we did. The cruise line (Princess) were fantastic. They took copies of all of our docs relating to our flight bookings and lost baggage claim and assured us that they would be calling BA @ MIA airport 3 times a day to follow up and get our luggage. The cruise line gave us a whole range of complimentary toiletries and unlimited same day laundry service (no charge) for the limited clothes which we had.
We received our luggage 2 days later after the BA staff@ MIA airport forwarded it on an AA flight to Grand Cayman where our ship was due that particular day. The Princess port agent collected the luggage from the airport and delivered it to the ship. We were relieved and amazed that they did what they promised.
After returning home I submitted a claim online to BA and in less than a week I had a call from BA informing me that our claim had been approved and the funds were in my bank a few days later.
Hope this may help you in this stressful situation.
Last edited by simon stingray; Feb 26, 2020 at 4:31 am
Reason: typo