I sent them 980 EUR on 04/12/2017 via SWIFT transfer with valid beneficiary parameter.
They have been keeping me on hold ever since. They cannot locate the money and keep asking me to be patient.
Its been 6 months now.
Is there a way for internationals to pressure cex.io other than support mails?
6 months? That's a long time.
If you have the right details on your transfer and you are sure of that, then there is virtually no reason for such a long delay. But cex.io's fiat payment processing is definitely not something that you want to trust, as shown by history.
You should be able to get a quick response if you send a message CEX on this forum with a link to this thread, so that they can respond publicly to this issue. But apparently they use a third party payment processor for their fiat transactions, which is causing the delays (doesn't excuse them one bit for the delay). BTW, do post some proof in the form of screenshots.