Had full body laser done 2 years ago (8-12 treatments 4-6 weeks interval) hair has been back and thick. What should I do?

8-12 treatments should be quite effective.  Results may vary greatly based upon your individual body, the quality of the equipment, the equipment settings, the timing of treatments, and the provider technique and experience. 
I would consider further laser hair treatments.  Electrolysis is just too slow and tedious.  I would only use electrolysis for light hair and hair in areas that can not be lasered, such as around the eyes.
Before further treatment I would consult your physician to ensure you do not have any health conditions that might affect hair growth - mainly hormone related. 
Best of luck!

Thank you for your question.  Your should be able to maintain 90-95% hair reduction after a series of LHR from a quality provider using well maintained/powerful equipment.  Either the equipment / settings used weren't appropriate or you may have an underlying hormonal issue.  Best of luck.