Discovery sending my credit card details and balances to others

The only reason I gave a 1 star rating is because it seems like I can't give a zero. I have phoned and emailed numerous times with no response from Discovery. They are sending my credit card information and balance to someone I have never used as a contact. Every time I make a transaction, the details of the transaction with my credit card balance gets send to this person. I have queried this and how / why they are sending my information to someone else but I can't get any answers. This has been happening since they changed my credit card from FNB to discovery bank. How did discovery even link this person to my profile?