Looking for a stronger replacement
I'm afraid that the manufacturer doesn't really make a sturdier version of this handle set. In this industry, a company tends to make one version of a thing and that's more or less it.
I can tell you that one thing that would help alleviate future damage like you describe would be to clean and lubricate the rollers and track to make sure they're running smoothly. A patio glass door should be able to open with a gentle touch; if you find yourself having to really pull on a door then this will cause wear over time.
I'm sorry we cannot offer a better replacement option for you.
Great! Be sure and get back in touch with us and let us know how everything worked out.