LazyPay — Getting messages which says to clear dues or you will get penalties

We don't know anything about the lazypay app till Jan 15 when we started getting messages about some due amount. We haven't even downloaded the lazypay app then how can we used their services. The amount in the messages got increased from message to message. Today we received a call from the customer service saying that they represent lazypay and things. Please look into this matter soon as we are getting irritated otherwise we will be going to the law enforcement soon.