An amalgam of the word 'batty' (Jamaican Patois for 'butt', 'arse', 'ass', 'bum'; and 'clunge' a relatively new term for 'vagina', gaining possible popularity as it's not necessary to sensor like the full on version of the word 'c*nt'.
Together the words making 'battyclunge' refer 2 a submissive anal sexual act, possibly gay-related cuss yet again. Literally meaning 'mansnatch' 'ass-screwing hole', it calls out on a person's doormat tendencies, as in 'bending over' for anything, being a mug 2 oneself, letting others pull a fast one over you and hussle you.
what he sold you was rubbish, and you paid top whack? you Battyclunge (Batty Clunge, Batty-Clunge)! You've been mugged off!