LazyPay — harassing to clear the dues

I booked a ticket on redbus but it was a failed transaction. So i got a link on whatsapp that i can still book a ticket and pay later. I clicked on the link but the ticket booked was for some other date.

I immediately had to cancel the ticket. So i get a msg that i need to pay the cancellation amount to lazypay.

So, first, it was a wrong ticket booked by the app and then they are harassing me to clear the outstanding dues.