Crew or cleaning staff are *******

I flew BA last week Friday from Cape Town.I receieved some bad news and ended up forgetting my laptop on my seat. I was the last passenger to disembark, I distinctly remember seeing 3 flight attendants right behind me. I realised my mistake when I got home, and called the airline. They said nothing has been handed in. I've been calling every day, and still nothing. A staff member took my laptop... they are *******, and BA has not been helpful. I asked if it would be possible to follow up with the staff members that were on the aircraft, including cleaners. But no help. So they enable their thieving staff by not following up...