FNB Not Serious About Bank Account Security

I've been receiving sms notifications for a account that is not mine. I notified FNB (First National Bank) with this issues and asked them to stop these sms notification. Firstly I went into the Branch and I was told they can't stop it, I than call the FNB customer care only to be told that they can't just stop the sms from come through due to the account being a business account.

I was worried that FNB is not serious about the security of our accounts, to me this cause a serious security risk, should the owner of that business account make changes online the OTP will come into my cell number, that might create a security breach on that Business account. I spoke to 3 different customer care personal, Up until this moment I'm still receiving notifications for every transaction that is happening on that account.