U2713H, Flickering

My monitor started to flicker white horizontal lines. This has been happening for some time but has been intermittent. However, it been getting worse until now it hasn't come right. So off I went to the Dell support,  I found a video to trouble shoot this problem and following the instructions I isolated the monitor - only the power cord plugged it and the self test box that floats around was showing the same problem pressing buttons 1 and 4 together to bring up the diagnostics shows the same problem. So clearly this is a problem with the monitor and it need to go back to Dell for repair / replacement. However my frustration lies is that I try phone Dell to find out where is the nearest service centre to drop this of and the number given says I can call between 9am - 6pm AEST (Australian Eastern Standard time). I'm in Western Australia and there is a 2 hour difference but after a unhelpful lengthy automated menus system I get told that I need to call during office hours? it's was 10:00am which is 12pm AEST - and it's Friday so I'm trying to do this during office hours! So next I'll try send them an email so I choose email from the option and it then automatically enters my service tag and when I click next it ells me that it doesn't recognize the service tag?  But it did when I added it to my account as one of the products I have? I'm in Bunbury WA and all I want to do is have the monitor send in to either be replaced or repaired So who and how do I contact someone to get this information!