No response from gotogate after changing flight

<p>I booked a flight CPT Lisbon via Dubai and 5 days ago they emailed to say within 5 days I needed to accept another return flight or they would leave the one I had booked but could not guarantee getting on the flight. My complaint is that they are impossible to get hold of .....I want to sort this out naturally before the 5 day deadline they imposed is up but they can only email. Getting through on their landline is impossible. I have emailed several times asking for confirmation of which flight I am now booked on but not a word. </p>