CHICAGO — In a cold basement apartment on the Southwest Side, Gregorio Pillado and Martina Alonso count pennies and pray for relief. Pillado, 79, has been working at a nearby meatpacking plant for 20 years, lifting thousands of pounds of frozen meats into large vats, eight hours a day, five days a week. His $16 an hour pretax is the married couple’s only source of income. With it, they manage to pay for their groceries, medicines, utilities and their $800 monthly rent — but not much else. Alonso, 69, used to bring in money by catering small parties and selling bags of chopped-up nopales (prick…