Ratcheting up her demand for withdrawal of the Narendra Modi-led central government's decision to demonetise Rs 500 and Rs 1,000 currency notes, West Bengal Chief Minister Mamata Banerjee on Saturday said the move has turned out to be a "big black scandal"."This has turned out to be a big black scandal. Hardship for the common citizens and full advantage to the money launderers. I have said this before, but given the way the young, old and everyone is suffering let me again appeal to the Central government to withdraw this 'black' political decision which is anti-commoner," Banerjee tweeted.The Trinamool Congress supremo, who has penned a poem decrying demonetisation, noted that India's purchasing power was crashing."Markets across India ruined, purchasing power crashing, people in pain," she said in another tweet.Delhi Chief Minister Arvind Kejriwal on Saturday demanded rollback of the decision to demonetise, saying that the economy will collapse in the coming days if the decision was not withdrawn.