Please follow these few steps:
Step 1: Contact our Customer Careline at +603 50223888 to immediately suspend your Touch 'n Go eWallet account. This is to protect your balance in your Touch 'n Go eWallet account.
Step 2: Contact your mobile service provider to block your SIM card immediately to avoid any attempt to request OTP to reset your Touch 'n Go eWallet password/ PIN.
After you have recovered your mobile number with your telco, we highly recommend that you reset your Touch 'n Go eWallet PIN as an extra step of precaution.
Below are the articles that may be useful for you :
Is my personal information safe?
How do I ensure that my account is secure?
Why is the Touch ‘n Go eWallet app not supported on jailbroken / rooted devices?