I WANT MY MONEY BACK

hi,i did everything they asked me to do it, they debited on my account 790 they said its for 200 is shipping and 590 is my first instalment it was on 23 May even now i haven't got my hair ,nd then i panicked called my bank to suspend mandate and dispute the money ,unfortunately i could dispute the money ,after i called so may times they said they will deliver the hair ,after two weeks they said they will delivery still now ,i have trusted them with my money on my bank but they say they are not gonna delivery until i finish paying, why must i trust them after so many disappointment ..