Question: What was the answer to Lot's people?
And his people gave NO answer but this: They said, "Drive them out of your city: these are indeed men who want to be clean and pure!" -- Sura 7:82 & 27:56
But his people gave NO answer but this: They said: "Bring us the Wrath of Allah if thou tellest the truth." -- Sura 29:29
Obviously the answer is different. And since it says both times "no answer but this" they could not have said both with one part reported in one sura and the other part in another, because then there would be "another answer" contradicting the "no answer but this".
Answer: Very Simple: I would suspect the Lot talked to his people several times and they gave him two answers, God knows may be even more.
7:82 And his people gave no answer but this: they said, "Drive them out of your city: these are indeed men who want to be clean and pure!"
وَمَا كَانَ جَوَابَ قَوْمِهِ إِلاَّ أَن قَالُواْ أَخْرِجُوهُم مِّن قَرْيَتِكُمْ إِنَّهُمْ أُنَاسٌ يَتَطَهَّرُونَ
29:29 "Do ye indeed approach men, and cut off the highway?- and practise wickedness (even) in your councils?" But his people gave no answer but this: they said: "Bring us the Wrath of Allah if thou tellest the truth."
أَئِنَّكُمْ لَتَأْتُونَ الرِّجَالَ وَتَقْطَعُونَ السَّبِيلَ وَتَأْتُونَ فِي نَادِيكُمُ الْمُنكَرَ فَمَا كَانَ جَوَابَ قَوْمِهِ إِلَّا أَن قَالُوا ائْتِنَا بِعَذَابِ اللَّهِ إِن كُنتَ مِنَ الصَّادِقِينَ