Vodacom SIM swap

Hi please please could someone from Vodacom explain why it's so difficult to do a SIM swap I tried numerous times dialling your call centre but as soon as I put in my number line goed dead tried on Vodacom pay app it says try again later tried on Tobi said a consultant will call me but still no help my number is *** if someone could help would be great I even went on FB sebt Vodacom a message nothing