Where they really in hell?

The constant question was asked throughout the play, where are the torture devices? At the end of the play, we find out that the room they are trapped in is their hell and the people in it are the torture devices. While this is an interesting interpretation of hell, what if the reason for this "hell' for being so different is because our trio is not hell but actually in limbo. I asked this because of their setting, they're trapped in a room. From what I know about  Limbo is that those who are trapped there an in a sort of waiting room kind of place, their reason for being in this place is to sever for their sins, but eventually, they will reach heaven. Limbo also does not seem to have the typical torture devices, most depictions in movies and novels show the inhabitants dealing with a mental type of torture. What really led me to ask this question was at the moment in the play when the door opened, what if the opening of the door signified that they had served their torture and the moved on to the next level of their spiritual life?