Refund for cosmetics

I need help with signature in kamptone park I brought cosmetic and the card said Decline but the transection went through,so I ask them what do we do thy said I must come back with a bank statement I did tht and thy promise to return my money evn today I have not got it and I ddnt get my stuff that I brought Nothing ,and they are giving me a run around it like thy are taking me for a ride nw.