what happens if you ignore dacion en pago and just chuck the keys in?

Hi everyone. Thanks for all your generally kind and understanding comments on my Roda postings. I'm about to bail out and hopefully skip the dacion pago stuff as I have already lost pretty much all my life savings, and with no realistic end in sight. The other costs and charges are still running at way over £60 per week, plus the mortgage and it's all simply unsustainable. I've read all about the dacion scheme and even there, rip-off continues, so I really don't intend to play that particular game. Big question is, "What happens if you just give them the keys back?" Maria kindly suggested a form of letter which I understand obviates the dacion performance, and I hope she'll arrange to do one. Still a few weeks to go. Have an almost new Air-con system and meter for sale, will suit Roda 2 bed apartment.  Can arrange installation. Cheers, Rollo