He did allocate a bunch of funds for the wall but people were never going to get everything in that regards. The mexico will pay for it thing was just some random stuff he said at a rally, it was never a promise or anything.
According to BBC News, it was his signature promise, as I remember hearing Donald say it multiple times. https://www.bbc.com/news/world-us-canada-46824649 What if politicians secured in a bitcoin multisig their promises? I wonder how quickly their tune would change when they actually had to keep them or they would lose something if they didn't.