MTN promoting ****s

I regret the day I signed a contract with MTN.MTN is a ****, especially these days, we are living in. They gave me a SIM card of their previous customer. Am receiving all debit orders of this guy from his cash withdrawal. Payment of the account, the outstanding balance of accounts even having his ID number. I even know his payday. when I called MTN on the matter, I was told that’s how they recycle the SIM card. So if you take a contract with MTN or use their SimCard keep in mind your information is not safe if u stop using that number or u can share a number with another user. They are not willing to assist me, They only want me to make payment as per the contract,MTN a ****.