Raj waterproofing Service - Waterproofing Service Issue

I was looking for the waterproofing solution for my terrace shed....I have been contacted by Raj waterproofing through WhatsApp and call....and fixed the meeting to see the work needs to be done, decided the total amount **** to pay for the service with * yrs on guarantee with Dr.fixit material...and I asked them to start the work.
The owner of service firm Raj Sonawane asked me to pay the advance Rs.**** on **th April'**** for material cost and to start the work.
He started the work on **th April'**** and completed the work on the same day, saying if during raining if it's still leaking then he visit again fix it completely. I did the final payment of remaining amount Rs.****....I asked for receipt but he denied for any receipt or guarantee documents for the service.
After a month during the initial rainy season the both the terrace shed started leaking so I called him to visit and check the problem....he did not come for visit so I started following him on call but he didn't respond to my calls and even messages.

The waterproofing Service details as below.
Raj Sonawane - **********
Pooja Sonawane - **********