Fill in the customer complaint form online. You can send a complaint any way you want, but it will eventually be scanned into the database that this form feeds directly, it will simply be delayed 4-6 weeks. The form allows you as much as 2,000 characters, but try to keep your complaint to 3 short sentences. There is a link at the bottom of this post. You can also find it on united.com.

While I hope that this never happens again, this ought to have been raised to the Captain after arrival.

https://www.united.com/web/en-US/con...r/default.aspx