Inspiron 545 MT Wireless Internet not working!!

About two days after recieving my new Inspiron 545 MT, the wireless stopped working, the wireless still works on my laptop so i know my router is ok. My internet also works fine with a LAN cable.

I tried deleting the windows upgrades as i thought they might be causing the problem and have also rebooted from factory settings. This worked temporarily and i had my wireless again for about another day. I have tried the Dell diagnostic tools but they say everything is fine and have also tried reinstalling the drivers for the wireless card (1505 Draft 802.11n WLAN minicard) . None of this worked so i tried rebooting again and now that wont work either. Ive been trying to fix this for nearly three days!

Any help at all would be welcome because im frustrated and ready to send it back.

Thanks