You need to talk to a lawyer who is experienced in military law who can look at the orders to properly advise you. But, what your Recruiter probably never told you was that when you enlisted, it was for an 8 year period, which is mandatory under current federal law. Your "discharge" was not from the Army, it was a discharge from your active duty obligation, and until the 8 years are up, you would have been assigned to the Army's IRR [inactive reserves]. If you are in the IRR you can be mobilized and then kept beyond the 8 year period.
There is a process to contest the mobilization, but it's pretty complicated to do it correctly, so again, you should consult with an experienced military lawyer.
What is your obligation period? Do you still have an ID Card? Did you retain a copy of your DD 214? Do you have your enlistment documents? Did you copy your 201 file? All these things will assist an attorney who knows the system to review those orders and make a call to personnel to investigate this for you. Don't wait too long though if you have been activated.
This answer is provided for informational purposes only. Actual legal advice can only be provided in an office consultation by an attorney licensed in your jurisdiction, with experience in the area of law in which your concern lies.
