Cannot connect on 5GHz

I feel really good after reading all of the posts. I am not a total fool after all. I am the same as you guys. Have a N600 router and bought a WN2500 extender. Same prob no 5GHz. I went thru 4 email help sessions, was going nowhere telephoned Gearhead services, it was outlined at bottom of the emails. Was advised it would cost. Desperate I signed up for 6 months $90 Australian. The first consultant was on the phone with me for over an hour. Finally agreed the Extender was a dud. I swapped it at the Retailer. Installed new one. Same problem, the firmware forces the 5GHz to adopt some 2.4 GHz settings. Second Consultant could not effect a fix, so took over control of my PC, hooked the Extender to an old Netbook and I monitored my iPad. Exactly how he forced the setup is beyond me, but I finally have both 2.4 & 5GHz. In Australia best retail for Extender is $90.00. Fee for Gearhead is $90.00.
You guys are right, there is a huge dog in Netgear's kennel. It will take quite a bit of good PR for me to buy anymore of their hardware.