Spirit Airlines announced Sunday it had largely completed refunding passengers and returning its crew to their home bases, following its abrupt decision to cease all operations over the weekend. The carrier collapsed under severe financial pressures, including a sharp rise in fuel costs exacerbated by the Iran War, leading to the cancellation of thousands of flights and stranding travelers across the U.S., the Caribbean, and Latin America. The airline, which had over 4,000 domestic flights scheduled through mid-May, stated that most customers who booked with credit or debit cards had been refunded by Saturday evening, with a small percentage still being processed. A Spirit Airlines message for customers is seen on a pamphlet after the company ceased global operations at Fort Lauderdale-Hollywood International Airport (AFP/Getty) However, some passengers reported difficulties. Jessica Stanton, who flew from Myrtle Beach to Boston for her college graduation, received an email Friday canceling her return trip.…