Dev was such a fool, he didn't even realize what his mom saying. She would have allowed Sona if she knew Sona was with her. Really? Dev didn't question her in that aspect. He was only thinking he missed Soha because of his mom, when will he realize he lost Sona also because of her Mom. When will he accepts his mistakes and find permanent solution.
After 7 years also his character is wandering in vein, not able to take a stand for truth, CVs pity on you guys thinking. Focus on improving Dev character, and stop making Sona prove her innocence again and again. It is frustrating.