Sharing my Contract Sim Card with someone else.

I have bought two Samsung A30s on contract delivered last week (7days ago). As I am using the main contract sim card and my partner is using the secondary sim card, he has been experiencing problems with the sim card ever since. He has been receiving phone calls, SMS's, how much airtime he recharges and even WhatsApp messages coming in for the guy by the name of Rian, I mean this guy's details are being exposed from bank notifications to WhatsApp messages his security is being compromised miserably.

I went to the Vodacom shop in Centurion Mall to query about this matter, a lady who was supposed to assist me gave me a customer service care number( ***) to call, till today I have not received any help instead I am being SMS'd a number to contact a robot by the name of Cobi which I tried and sadly told me that my number is not registered with vodacom. I have been trying all these customer service numbers and still nothing good has never come out of it.

I am deeply disappointed by Vodacom services whereas they're failing to provide honest services to its customers.