MAC and Things unauthorized purchase

A company called MAC and Things just processed a debit card purchase on my FNB account and since Saturday I've been pushed from pillar to post with FNB. Currently I am on hold for their ***** department for the last 15minutes.

This is ridiculous, I did not authorize this purchase whether it was online or instore. I need FNB to advise on what is happening as I see that since the weekend their are numerous complaints logged about this and FNB is not being helpful and protecting their clients.