A friend of mine was whining how work scheduled him on a day he requested off. He showed me a text message convo with his manager where the manager said something like, yeah you shouldn't have been scheduled...well, come anyways, sorry.
My friend said he wanted to keep the texts for some purpose or other, then I stopped him.
"See, while you do have an electronic paper trail, it is useless. The words 'must' and 'shall' have similar but very distinct meanings in legal filings. 'Shall' is used when in a perfect world a party gets what it wants, whether it be this that or the other. 'Must' is used when a party MUST get what it wants come hell or high water. So while you do have the """receipts""" as the kids say, your manager used the word "should"; rather, "should not", so you have no recourse. Therefore, your complaint is a charade.
"In other words you're fucked and should go to work."