when facebook tells you to submit phone verification code that means u can't unlock ur acc
unless u submit p/v , there is no choice but to verify ur acc by phone .
there 's been a way had worked before , but im not sure if it would work :
get in fb help center and tell them that ur account was exposed ( hacked )
follow the steps that appear , but this old way almost wouldn't work since fb declared
the war against spammers
hire a freelancer presents phone verification service but note : some members present this service free for one or two accounts