L'Oasis des filles perdues (1981)

Freewheeling female friends Annie and Nadine are snatched during a night of rump-shaking discotheque shenanigans by an evil slavery ring. Drugged and gagged, the gals wake up in the "Oasis", a clandestine bordello nestled deep in the African Congo where they - and a gaggle of girl prisoners from all over the world.