“Airlines are making a clear and genuine effort at strengthening the attention paid to customer service, but bottom-line results to date are mixed,” the department’s inspector general said in a preliminary report to Congress. “The airlines have a way to go to restore consumer confidence.” In fact, complaints were up 74 percent in the first four months of 2000 when compared with the same period in 1999 — 6,916 to 3,985. Delay complaints, the department’s top complaint about airlines — were up 80 percent — 2,842 in the first four months of 2000, compared with 1,546 in the same period last year.