You recieved info during your onboarding I'm sure (since every employee does) stating that overtime starts at 40 hrs. but that part time associate's shouldn't ever consistantly work that. I'm sure you also got a phone number to report abuses like that, and it sounds like there's a problem with the mgt. of that store and that IT has a very high turnover rate, because v.s. has a decent retention rate. By submitting this letter, since corporate policy is already in place against these violations, it's only going to come back on your store's mgt.