EX010300509SG my seller re shipped my product is it from Ems?

hii i have placed order for cell phone..few days later seller informed me that my product was sent back as it contained battery. he sent me this number EX010300509SG. what is this number? if it's a tracking number..is it EMS of FedEx?? some one help"
(first time EE799603198CN i got this as my tracking number and later it was sent back..EMS)