Double debited

I went to buy at Link Pharnacy and swipped my FNB card the transaction was declined twice and I went to withdraw and paid them cash R150.00but actually went off my bank account , when I received the incontact message from my bank I went back to the pharmacy to be refunded, they said I must wait for 24hrs the funds will be reversed back into my account until today nothing has happened and It means that I paid twice for one transaction . I have been driving back to the pharmacy for the refund without any help they say that I need to call the bank myself and already I have waisted my petrol going back and from. Please help me to resolve this