On hold for 15 to 18minutes

Wooooow I was on hold for 15 minutes with Sfiso Mdluli, he did not even bother to come back and explain what's the hold. I requested for a manager and I could hear from his tone that he was very irritated when I asked for a manager and I know he was just getting back at me. I need to know what was he doing in that 15 to 18 minutes please check cameras this Sfiso must be taught a lesson we are customers and we use our airtime to call just imcase he has forgotten. How do u put someone on hold for a deck 15minutes????? Number I called was ********** 222 at around 7:40 am