That is the price you pay when you store your coins with a third party such as an exchange. They are no longer your coins - they belong to the exchange, the exchange can do whatever they like with them, and there is nothing you can do about it except wait for their awful customer support to get to your ticket in a few days/weeks/months. If you don't like their answer, tough. In future, you should withdraw any and all coins from Coinbase immediately after purchasing and hold them in your own wallet where you, and only you, control the private keys.

Because customer support is expensive. Why waste money on employing more staff when they can just increase their profits instead. You have just proved exactly why they don't need to provide better support: Even when users have terrible experiences with Coinbase and share them online, instead of people saying "Oh my god, that's terrible, I'm going to withdraw my coins immediately so it doesn't happen to me", users like yourself say "Well, it hasn't happen to me, so I'll just keep using Coinbase". Everyone thinks it only happens to other people until it happens to them, at which point it is too late to get your coins back. People continue to make post after post after post about how terrible Coinbase is, and users like yourself continue to ignore them until it is too late.

There is a reason that there is an entire #deletecoinbase campaign. Do yourself a favor and take control of your own keys and your own coins.