Standard Bank recycles accounts???

I recently discovered that an account number i used over 5 years ago from Standard Bank was recycled and given to their new client. I recently made a claim to my medical aid scheme where that account number was used and money was paid to the account number that was recycled and it landed safely in their client's account. My query to Standard Bank is what measures do you put in place to ensure that such errors do not happen? How can a transfer go through with my details to your new client?Why recycle accounts, such a security hazard?And finally how is the bank going to ensure my money is paid back to me?