Overtime? No overtime?

Should we be forced to do overtime? Even more so during the run up to Christmas, we are expected to put in all the hours we can. I suppose this will suit quite a lot of people, with Christmas getting more and more costly. But what about people on tax credits and benefits? I myself had to pay back over £200 pounds last month because of an over payment from housing benefit and tax credits. All because a staff shortage on department and being "forced" to do overtime. I use the word "forced" slightly ambitiously as I wasn't held at gun point or anything but, was certainly named and shamed if I asked to leave. I suppose it could be called bullying but to be truthful, a manager needing the work to be done is, in my opinion, a manager doing what he's payed to do. Its just finding that point where the department becomes more important that the individual and hoping the boss doesn't cross it.