Bitter after his own defeat and his party's debacle in the West Bengal Assembly polls, BJP MP Babul Supriyo on Sunday night refused to congratulate Mamata Banerjee on her party's emphatic victory. In an angry post of facebook, Supriyo, who lost the Tollyganj seat, said the Bengali voters had made a "historic mistake" and lashed out at party chief Mamata Banerjee, whom he labelled a "cruel lady". "Neither will I congratulate Mamata Banerjee... nor do I wish to say I 'respect' the people's verdict... sincerely think people of Bengal made a historic mistake by not giving BJP a chance... by electing this corrupt, incapable, dishonest government and a cruel lady back to power," he ranted.