Frustrated customer

Ever since I took a phone in November 2019, my personal information has been compromised. ********** accounts have been opened and I having to contact the retailers for them to stop these accounts and going to SAPS for affidavits. I even went further to ask the SAFPS to flag my ID in order for me to have a peace of mind but still, this is continuing. I have never lost my ID and the only time my personal information was requested from me was when I took a phone with MTN. Could it be that leaving copies of my ID, Payslip and proof of residence was wrong of me hence this info is required when signing up for a contract. I really dont understand this. Can someone at MTN clarify this for me.