Do RCA’s have to answer when there not scheduled?

I wasn’t scheduled to work this week and yesterday morning I got 4 calls from my PM at 7 in the morning I didn’t answer because the post office doesn’t pay my phone bill. She just called and said that I need to answer the phone and all of this other bs and says I am needed out of town and I HAVE to go. When I went to rca academy we was told we don’t have to answer our phone on our days off. Is this true and if anyone is able to can you show me that in the contract?