Double payment

I paid up my loan on Wednesday they sent a paid up email to me, they again tried to debit me on Friday and sent a message I contacted support to tell them to not debit cause I paid them, they debited my account today, when I go to their Facebook page they send me to support and tell me about 4 hours when I haven’t received any response for more than 18 hours and I paid them twice in a month (Setteled the account and they still debited) I want my refund