If you purchased the units new through a local reseller, contact them and let them know about the licensing issue -- they should be able to clear up any issues with those units.
The only times I encountered a licensing issue is when another customer' s unit was registered to our company by mistake and when an RMA unit got the wrong serial number " embedded" into the firmware.
That said, I suggest verifying the serial numbers on the back/bottom of the units against what is listed in the GUI/boot menu vs what is listed on the box/invoice. I would then log into your account on fortinet and check to see if the units are not already registered. Contact your local reseller if you find a problem. Otherwise, contact customer support in your region.
NSE4/FMG-VM64/FortiAnalyzer-VM/6.0 (FWF30E/FW92D/FGT200D/FGT101E/FGT81E)/ FAP220B/221C