I signed up with Three with my mobile phone in July last year, and got a new phone with the deal, a Sony Ericsson z800i.
I've had issues with the phone since before January this year, where the phone would completely lose connection with the Three network, but would still show full signal. When it did this the phone would be completely useless as I could not make or receive calls or messages, and I would have to power cycle the phone before it would work (and all the messages I had been sent in the meantime would all arrive at once).
This was really annoying as I had missed some very important phone calls, and it was only through luck that I managed to notice it was playing up at the time.
I've been ringing Three Customer Care periodically about this problem. The issue was that I couldn't ring Three on my mobile if it was playing up, and I didn't see much sense in ringing Three about the fault if it wasn't playing up, so as a result I only rang Three about the problem whenever I noticed I had a problem at work and could use the work phone to ring, and I had the time. This ended up being about one call a month or so, out of the many times it played up.
Every time I rang them I had to explain it to the person at the other end again, and then once they understood what I was on about, they would go through the next step in the trouble-shooting procedures. So, I would do whatever it was they told me to do, reset the phone and then wait until it happened again and I was in a position to call them. One of the things they kept on saying what that where i live is right on the edge of a Three zone, which means that it would be constantly picking up the Three network, and loosing it and going back to the roaming network (Telstra), and they seemed to think that this was the problem. I didn't believe them as I had this happen while I was in Melbourne city, which is unlikely to be right on the edge of a Three zone.
I spoke with them at the end of June and they finally said to bring the phone in for them to have a look at. I took it in, they replaced the antenna, and I hoped that was it. However it wasn't, and they were out of ideas, so I gave them one. I borrowed a spare phone from paradigmshifty and used it to make sure that it isn't a problem with my location. I have not had any problems with the loan phone at all (other than it chewing through the battery like crazy whenever I am at home, showing that it is having problems with the network). However, since I haven't been having any problems, I haven't remembered that I needed to talk to Three about it again, until today.
Since I am about to be visiting Melbourne, I thought it would be nice if I could return the loan phone to the person who owned it, so I put my Sim card back in my phone, and rang Three about the phone.
Since the phone is now out of warranty, they are refusing to do anything without me having to pay for it. Not fucking happy. I am currently paying $15 a month for this phone, a phone that doesn't fucking work. I do not believe that this is acceptable, and I have emailed Three with my opinion (though with a lot more polite English). If I don't get some joy from my complaint, I am going to kick up a stink about it. The phone that I bought in good faith is not performing as advertised. We will see what happens from here.