speak or not speak spanish that is the question???

I work in a clinic setting as a medical assistant, our company has recently changed new management. This company has brought in a new supervisor in our floor who is very arrogant, rude and degrading to us. It has come to the point were we can't say, do or express our selves in any way or form. The unit is know to have a high hispanic population were as myself and another MA do the spanish patients or translate when needed. My co-worker and I have been reprimanded for speaking spanish among our selves (but never in wrinting)none of our other co-workers have express a concern or complained about us, In fact we are considered the most professional employees in our unit, I am the lead medical assistant. Yesterday another confrontation occured that has left me bother. Myself and another hospital employee went to punch out my time card. Once I did this my co-worker came into the office and punched her card out for the day. The person that was with me greeted my co-worker in spanish........my supervisor heard this and started telling the other person how she is not allowed to speak the language and how rude of her to this. Are we not allowed to speak spanish anymore even on our own time? this is getting out of control. what can I do? what are my rights? we have not received anything from our company telling us that we are not allowed to speak any language........................