Automatically opted out of out-of-bundle limit lock

I realised that I was receiving push notifications that would require data of which I knew I don't have. I loaded a page just to check if my connection was ON and the page loaded then checked and saw its using out-of-bundle billing. I contacted vodacom, asked them how did that happen that I was opted into out-of-bundle billing and was told its a system glitch. Was told it happens often to other customers as well I should always make sure my limit lock is active before I buy a new data and when it gets depleted.

Please becareful vodacom users out there, I know this is no system glitch. This is vodacom we're talking about.

I'm aware vodacom made a significant amount of profit from out of bundle billing. So I don't buy "system glitch"