How long do copper bracelets last?

I bought a gold plated Sabona copper bracelet about 20 years ago and was told by the company that it would last about 2 years.

When the copper is gone, what does the bracelet become?

I also have several copper bracelets. Does the copper decrease in strength? And does a copper bracelet become some other metal if the copper disappears? Thanks for helping me with this confusing issue.