Coinbase support is legendarily awful. This forum, reddit, twitter, medium and elsewhere are filled with stories of people submitting multiple tickets/emails/calls over several months and only ever getting automated replies that solve nothing. 3 weeks to simply change the number that displays on your account is utter nonsense. They don't even have to make a transaction, since the 32 BTC was sent out from, and then returned to, their main central hot wallet.

There seem to be two ways to actually get them to respond to your case: Cause enough of a ruckus on social media platforms, or pursue legal action. Here is a list of all their social media channels: https://support.coinbase.com/customer/en/portal/articles/1766604. I would suggest opening threads and trying to get some traction in /r/bitcoin and /r/cryptocurrency, on twitter, and on medium. Often if a thread hits the front page of one of the crypto subreddits, it suddenly goes from "months without a response" to "solved within a few hours".

If that fails, then I would escalate to a court order, since we are talking about over a quarter of a million dollars. Your profile says you are located in Spain? I'm not familiar with Spanish law, but EU law certainly lets you file a payment order cross border in EU countries. Coinbase is registered in the UK and has UK offices. Have a look here: https://e-justice.europa.eu/content_order_for_payment_procedures-41-en.do

You could always email them and let them know you are escalating to court proceedings. That might be enough for them to actually take the 10 minutes required to handle your case.

And it goes without saying, once this is resolved, get your funds off Coinbase.