Spirit Airlines has almost finished refunding customers for flights abruptly canceled over the weekend as the company folded . The budget airline left thousands of customers and staff stranded after deciding on Saturday to pull the plug on a business that was struggling for years, before a surge in the price of jet fuel blew a new hole in its budget. Spirit had scheduled about 4,000 flights through 15 May, according to Reuters . The airline has not made a profit since 2019, according to CNBC . The company attempted unsuccessfully to restructure in recent years after two bankruptcy filings . The sharp rise in the cost of oil resulting from the US-Israeli war on Iran dealt the airline its death blow, Spirit said in a statement . “Unfortunately, despite the company’s best efforts, the recent material increase in oil prices and other pressures on the business have significantly impacted Spirit’s financial outlook,” the statement reads.…