King size mattress (Greenwich SE10)

Hello everyone, we have a king size mattress that is being replaced as is too soft for us. Not cos it's super soft, or damaged, we expected it to be harder. The mattress was bought in may last year, it's in great condition. The only thing that ever happened is hat our puppy pee on it 4 months ago, but I did clean it with vinager and baking powder etc, wnd we continue to use it with no smell or issues.
I can arrange pick up with the council but I thought that perhaps will be good for someone here.
Again, nothing is wrong with the mattress, it's just that I have back issues.
We are based in Greenwich "village", so will have to be collected from here ASAP.
Please bear in mind that you won't be able to fold it to transport it, or will require a lot of effort to do so as it's thick.