Does Walmart allow managers from Pickens, Easley, to schedule employees to be off on the days that want them to be off?

I need some serious answers on this one that involves a possible conspiracy. I have to two people in my family that work two different jobs one is a Walmart and the other is at BMW. For some reason these two people are always off on the same day and they both work on the same day. This never fails so I can always know when they both are going to be off and when they are going to work. Problem is they both say they have no say in the matter. Problem is i live next to people that have stolen my mail and i suspect know people that work at both places and they might be the ones telling these managers at these places to schedule them to work on these particular days. I believe it is done as a form of harassment towards me and family members. Please explain if any of this is possible.