San Ramon-based oil megalith Chevron has lost a bid to collect $101 million in refunded income taxes, the Ninth Circuit Appeals Court ruled Friday. Chevron claimed that Texaco, with which it merged in 2001, was owed the refund under the terms of a settlement with the federal government in 1988. But a panel of appellate judges said no. By the way, that settlement? Texaco agreed to it in order to end an investigation into charges that the company overcharged its customers between 1973 and 1981. The Energy Department ultimately forced Texaco to hand over $1.25 billion.