Generally, if there was no actual written employment contract guarantying the benefits (or a given salary/wage, for that matter), an employer may change them at will, including right before or as an employee starts. This is a consequence of all employment being "employment at will" in this country when there is no written contract.You can *try* suing based on the theory of "promissory estoppel", which *sometimes* will hold a non-contractual promise, such as in the advertising for a job, enforceable, but be warned: it is a very upill battle and not likely to be succeed (it gives you a chance, but that's all). The idea is that if someone makes you a promise (like of benefits or a certain wage) to do something (like take a job) and does so knowing that you would have to do something significant to your detriment (like quitting an existing job), then their promise, made intentionally with knowledge of the detriment to you, may be enforceable. But some hurdles you will face are:1) You'd have to show that they actually *knew* you'd be leaving a prior job just to take this job; 2) You'd have to show that your reliance on their promise was reasonable--and in an employment context, given "employment at will", it's tough to convince a court that it is reasonable to rely on any promise not put in writing specifically to you (at the least an offer letter, if not a contract);3) Given the 6 month vetting period, a court could also hold that it would not be reasonable to hold a promise binding for half-a-year--that is, that given so long a period of time, you should have expected the job, pay, and/or benefits would or could change.If a court were to enforce promissory estoppel, it might order the payment of compensation or that you get the benefits; but again, this is a longshot.If there are 26 of you, all--or at least a group of you--should get together to consult in detail with an employment law attorney about your options and the chances of legal action.