Please help

Hi, I am trying to reactivate my straight talk ZTE Z288L hotspot device and this message "Our records show that the SIM card number entered no longer can be used", shows up EVERY time I enter my SIM card number. I actually got this hotspot device so that I could use it with my daughter's Chromebook for her school work. I desperately need this problem fixed. ASAP. My daughter currently can't work on ANY of her school work as we don't have internet and now I can't get the hotspot activated or added to my phone or my daughter's school Chromebook. I have tried EVERYTHING I can think of. I even factory reset the hotspot but, still nothing. I really could use some help, PLEASE!! If anyone can help me with this problem I would really appreciate it, thank you. Tyffani