How long have you had the system? We had the exact same hardware. What you'll find is that the APs work fine without the controllers but not well with them. We had the equipment about 2 years ago and ran it for a year as a 'managed solution'. The only managed part, after speaking the Netgear engineers in the US, was that we were being fed beta firmwares for it, not released ones (basically helping them test it without realising, even though we purchased it from our supplier). Netgear will tell you that you have things in the way, dead spots, interference, etc. It was a load of waffle in our case and possibly yours too.
If you were me, you'd get rid of it, nothing good will come of those controllers; they're a waste of time, money, phone calls, paper and patience.