IMO, You'd better spend your money knocking that all down and properly building a new pier on a solid footer.

That's not a professional masonry job, so all you'd be doing is spending your money fixing someone else's DIY project. It likely doesn't have a proper footer or even one to begin with, the bond is off and the joints are a mess. It may be hollow too, and it shouldn't be.

If you have a trade school nearby with a masonry program, that'd be an approach to have it rebuilt with some skill and not at the full blast professional mason price.