It says it right there in the contract. If you sign shit without reading it as the employer, and have been paying it for 9 months, that's on you.

It would be another thing if it was immediately fixed but in either case, be it the employee or employer, if you've been doing it 9 months then that's on you. (If an employee had been getting underpaid - but still a legal amount - and didn't say anything for 9 months, I also think that's on them). Gotta read contracts folks.