I don't agree with this. This shows how low the country rates its workers. When the money was paid in December and they saw that it was a mistake, they should have addressed it and let the workers know that it would be deducted from their next salary. Since it was December salary, they might think its the bonuses they always receive bonuses previously.
Also the law also states that the deduction should be made from the the salaries of the next 3 months after the mistake was discovered. The mistake was discovered in December and according to them, they will continue deducting even after this month. With the cost of living in the country, its simply not fair to do that  to people. Other people cant pay for a mistake the government made.