https://greasyfork.org/en/discussions/greasyfork/284379-%F0%9D%9F%AD-%F0%9D%9F%B4%F0%9D%9F%B2%F0%9D%9F%B2-%F0%9D%9F%A0%F0%9D%9F%9A%F0%9D%9F%A1-%F0%9D%9F%AD%F0%9D%9F%AE-%F0%9D%9F%B4%F0%9D%9F%AF-how-much-does-british-airways-charge-to-change-a-flight