The person finding your mobile will require, UPI PIN for making any transaction. You need not worry if you have not stored your UPI pin on the same phone (in Notes etc).
You are however, advised to immediately block your mobile number with your mobile service provider thus no transaction can be initiated from the same mobile number.
In addition, please contact our customer support on 02261890111 or 0226189034 or write to mbank@bharatbank.co.in.