https://businessstrategy.louisville.edu/hc/en-us/community/posts/34859009922195-1-888-657-8380-How-long-do-I-have-to-cancel-a-Delta-flight-without-penalty
https://businessstrategy.louisville.edu/hc/en-us/community/posts/34859009922195-1-888-657-8380-How-long-do-I-have-to-cancel-a-Delta-flight-without-penalty