Transaction not yet processed

I have an unprocessed transaction on my statement which has been there since February 6th. Swiped my card at a specific store. Speed point lost network "apparently". Money went off on my account but the merchant stated that the transaction does not appear on their bank statements and refuse to refund me because of the previously mentioned. Tried consulting Capitec, as my bank, but all I get is jargon and vague answers. How long does this unprocessed transaction take to be cleared and returned to my account?