Based on this thread and the others it seems the problem is in tauranga but also wider bay of plenty. The final straw for me was looking at truenet and seeing that tcl was showing up very badly on the national statistics, what you can't tell is whether it is poor across the country or been particularly bad in tauranga area is dragging the nationaal average down, and it's been the same for a couple of months now.
Given their advertising campaign it brings to mind it should always be easier to keep a customer then to gain a new one. I would not be happy if I had just switched. What I must say is I was very pleasantly surprised as to how easy the switch was.