HELP! I entered my Card Details on a ***** site

So yesterday I called the FNB Premier Banking number - which I am now pretty sure, is just the same as the normal banking call centre, not sure why it's called "Premier" then, but that's besides the point for now..

Here's what happened: On Tuesday, 10 March, I received a voucher from Vodacom for a free online course at Shaw Academy, I then went to check it out thinking - surely it must be legit, since I received the voucher from a trusted service provider (Vodacom). I then proceeded to enroll for a course and entered my FNB card details which it says - won't be charged unless I do not cancel my subscription at the end of the free trial.

Then after that I decided to do a little more research on the credibility of the course that I enrolled for, only to come across review after review complaining that this institution keeps taking the monthly subscription fee even after customers had followed all steps to end it. Realizing that I too have now entered my card details on this ***** site, I quickly followed the steps to cancel my subscription and immediately called FNB Premier Banking - wanting to find out if there was anything I could do to PREVENT them from taking any payments from my account.

This was clearly too complicated, I was transferred 6 times, still with no one being able to advise me on what I can do. From so called Premier banking, I was transferred to your ***** department, from ***** I was transferred to Online Banking, From Online banking back to ***** and then another time, back to Online Card. At this point I was getting tired of re-explaining my story to 6 different people.

I want to know what I can do from my side to be proactive rather than wait until they have already taken my money. Even if it means I must cancel this card and request a new one (if that will work).

I fully intend to share my thoughts with Vodacom for sending these to their clients as well as leave my review to Shaw Academy.