Over 100 Fin24 users say they have also been hit by a SIM-swap scam that pilfers up to hundreds of thousands of rands from victims' bank accounts.

Fin24 reported on Wednesday about a SIM-swap scam that has affected First National Bank (FNB) customers who have MTN phone contracts.

Private consulting forensic scientist, Dr David Klatzow, says his client, Cape Town audiologistGail Jacklin, lost over R200 000 from the scam earlier this year. Dr Klatzow said his client hasn’t been reimbursed by FNB.

Dr Klatzow told Fin24 that MTN failed to prevent an unauthorised SIM-swap of Jacklin’s phone, which resulted in fraudsters stealing from her FNB accounts.

The SIM-swap scam allegedly involves bank customer’s phone going on the “blink”. Thereafter, the fraudsters execute an illegal SIM-swap and gain access to key info such as online banking One Time Pin (OTP) codes.

Dr Klatzow alleges that the scam involves an inside job at both FNB and MTN. Both FNB and MTN, though, have said they have secure systems and that users must beware of phishing scams.

However, dozens of Fin24 users have said they have also fallen victim to this scam, which operates with a similar modus operandi.

Below are just some of their stories.

Fin24 user Howard wrote:

"I had R5 000 stolen from me on January 5 2016 and FNB says I compromised my details. However working for Standard Bank for 17 years, I don't think I'm an idiot.

After numerous e-mails to MTN, I'm still waiting for details as to where and how the SIM-swap was done. This was sent to their fraud department who took my call once and promised me the world. I got what they needed and sent to them, but no response yet."

Fin24 user Halda speaks of a similar scam:

"There was a SIM-swap done on my MTN phone December 31 2015, and R18 500 stolen from my FNB account. I have opened fraud complaints with FNB & MTN. FNB only started investigating from last week, but still no comment from MTN!"

Fin24 user Zama wrote:

"I've also been a victim and I'm still trying to recover.  It's the worst thing that can happen to anybody and don't wish it upon anyone at all. Strict measures need to be put in place and the culprits need to be punished. The banks need to put the regain our trust once again.

What's frustrating is that the banks never give you proper feedback. It is like they are trying to cover for one another and forgetting about the end user who happens to be their customer.

It's not just that they also need to start investigation the fraudulent debits of R99.99 that go off and should warn clients on a regular basis."

Fin24 Ulze said:

"My parents one business lost R900k with this in Feb 2016.03.02 They also still waiting for the money to be returned!"

Another Fin24 user Jennifer has told of her experience with this fraud:

"Just read your article with great interest. I discovered that an MTN cellphone account had been opened in my name. I bank with FNB. Only discovered it on the second debit order, luckily for me FNB reversed both. I have never lost my ID or ever responded to a phishing email so I have no idea how my identity could have been used. I'm in Durban and the cellphone account was opened in Johannesburg.

Very interested to find out where this goes. Surely FNB should have alerted me that a debit order had been set up on my account, they have all my contact details.

But this scam appears to impact customers on other mobile networks and banks as well."

Fin24 user Charl has explained his experience:

"Exactly the same thing happened to me. Only I am a Telkom mobile and Absa client. My login details were not gained by the fraudsters through phishing. My cellphone became inoperable and a few hours later I noticed through my banking app that fraudulent transfers went off my bank account. I immediately contacted Absa fraud division and they locked my internet banking."

Fin24 user Linda said she experience this type of scam back in 2013.

"Hi There

I was also a victim to this but with MTN and Absa over the Easter Weekend of 2013. My father’s account was cleared out of all his life savings and my phone also went off.

The only way that someone could have known that my phone and my father’s account had anything to do with each other was if they had inside information.

After going to the banking ombudsman and MTN CEO I was told that it was my fault and that the bank and MTN were not to blame – not sure how they worked that out when it was their staff that committed the fraud.

Needless to say that my father was never reimbursed his money and he died late last year without knowing it had been taken as I didn’t tell him otherwise he would have died two years earlier."