Taarak Mehta Ka Ooltah Chashmah S01 E2609 The Real Culprits

"Problems Toh Hain Sabke Saath, Bas Nazariye Ki Hain Baat!"

Jethalal assures Champaklal that he hasn't given the ad in the newspaper. When Jethalal reaches Gada Electronics, he finds Nattu Kaka and Bagha celebrating. They both inform Jethalal that they were the ones who gave the ad in the newspaper. Why did Nattu Kaka and Bagha give the ad in the first place?