Not getting promised raises

I started working at Pizza Hut at the beginning of the year and was told I’d get a small raise after 90 days. I have never gotten my raise, everytime I try to discuss it with our area coach I am told I will have it on the next check, I’ve been told this numerous times and never received my raise. I am not the only one not getting paid right in this store, in fact, several employees have the same issue as I do or are still trying to get the correct pay after it somehow dropped randomly. Our area coach just has us write “Champs checks” each pay day to cover the money these employees are not receiving. This doesnt seem right..  or legal?? We’d just like to be paid properly and/or at least get told the TRUTH about why we’re not instead of continously being lied to or ignored.