Debit on my account without my permission

Two weeks back I was called by a lady from travel free who was promoting the travel free promotion I cant recall her name. she told me that they are running a promotion explained that this card it works in terms of accommodation I will just have to pay for food and its expired after two years. I ask her if there is any catch she said no because it was a promotion and she ask me the address where they can deliver the card I give her my physical address. I was surprise on Friday got a sms notification from my bank that there is a debit order of R400 that need to be settled luckily I didn't have sufficient funds now my bank is sending me messages that I need to settle the money because they going to charge me dishonoured charges and that will have an adverse effects on my credit scoring. I didn't give that lady my banking details so I don't know where she got them. Please fix this asap.