Pensioners with shares in Spain\'s nationalised financial giant Bankia say it cheated them into buying its stock, which has plummeted in value. Bankia has taken centre-stage in Spain\'s financial crisis in the past week, and the price of its shares, unwittingly bought by savers like pensioner Saturnino Lopez, 65, has slumped. \"It was simply a premeditated fraud,\" said Lopez as he waited on Thursday night for the start of an urgent meeting of small shareholders. \"I feel cheated because they said the shares they sold me had a lot of value and it turns out they were worth nothing.\" As the scale of bad loans at Bankia became apparent, its share price slumped, losing more than half of its value since it was listed last July. A retired energy worker, Lopez said he invested 25,000 euros in Bankia shares last year, and has watched much of his money evaporate with the declining stock. The Spanish state partly nationalised Bankia last week, the latest in a series of measures to strengthen a sector weakened by risky assets linked to a property boom that went bust in 2008. On Thursday the government and the bank fought off reports of a run on the bank by customers. \"We are talking about customers who had their savings deposited in the savings banks and were fraudulently brought on board for the stock launch in a time of crisis,\" said Fernando Herrero, leader of the financial consumer association ADICAE. It says Lopez and hundreds of thousands like him were invited to convert their deposits into shares without being told that the value of these was at risk from deteriorating property-linked assets. \"It was an easy way to raise a lot of capital with little effort,\" taking capital from lots of savers who as small shareholders did not gain any voting rights in the running of the firm, said Herrero. ADICAE said it would launch a joint lawsuit against the bank on behalf of 500,000 small shareholders. Bankia has 11 million customers. It was formed in 2010 from a merger of seven savings banks, part of a major restructuring aimed at preventing the overstretched financial sector from collapse. At the end of 2011 it had the biggest exposure of any Spanish bank to the property market, 37.5 billion euros, according to the Bank of Spain. Of these assets, 31.8 billion euros were classed as problematic -- mostly real estate loans with little chance of being repaid or repossessed houses and land whose value has plunged. Bankia shares recovered some ground on Friday, soaring 23.49 percent to close at 1.756 euros, but still far from their price of 3.75 euros when first listed in July, 2011. At that point \"it was already an unstable group, with a big exposure to property-related risk,\" said ADICAE\'s legal director, Santiago Perez. \"Despite all these circumstances, it carried out a massive sale of shares to its customers.\" Two sisters, Isabel and Miriam Sanchez, attended Thursday\'s meeting on behalf of their 80-year-old father who converted his 50,000 euros of savings into Bankia shares. \"They totally deceived him. They gave him very selective information when they sold him these shares, at a time when it seems the company was already doing badly,\" said Isabel, 37. \"The product was poisoned from the start,\" added Miriam, 34. On top of the 500,000 small shareholders, ADICAE says it is acting for some 120,000 people who in 2009 bought \"preferential\" stakes which were presented as secure deposits but have since lost a quarter of their value. \"We went to the bank that we have gone to for 42 years, since we were married,\" said Rosa Gimenez, 66, accompanied by her husband Felix, a retired industrial worker. \"They received us very kindly and offered us a product that they said was better value than a deposit,\" she said. The couple invested 33,000 euros in one of these \"preferential\" packages, thinking they would be able to access that amount at any time, like a regular deposit. On Thursday they received a letter telling them their investment had lost 25 percent of its value. \"It was a blatant con,\" said Rosa. \"If they had told us that we could not get the money back, we would not have done it.\"