Has anyone been getting charged extra for freight after paying the initial quote? The last two items I have sent have attracted an extra charge which is deemed a "job adjustment" In both cases it's been about 15% on top of the original fee. To the best of my knowledge the boards haven't expanded during transit! And yes I did measure correctly!
I have queried the charge via email but no response, not even an acknowledgement they've received my query. Does anyone know of a phone number or a further course of action I could take?

When you measured the board did you take into account the rocker of the board or just measured the thickness of the package? If the latter, then your measurement will be out.

Rocker was taken into account

Hey Smithy, is it possible that difference in declared v's actual weight may be the reason for additional charge? Rather than cube.

They may have made a mistake in measuring, it's not uncommon.

or a lot a freight (but generally not big items like a board) are measured by a laser measuring / cubing device. So if you have a bit of the packing or tape sticking up it will read that in the overall measurement.

been had by this as well. The rocker on the board is what you get nailed on as it passes through a scanner. while your box might be only 20cm thick (say 250cm long by 70cm wide by 20cm thick) the rocker means that if the board is say lying upside down on a flat table it will appear as about 40cm thick, which is the height from the top of the table to the top of the board, and you pay for this!
So its not really based on the true volume of the board (box). ego are a holes when it comes to this, smart send not much better.
For this reason, I go down to my local courier depot and get them to measure it and they tend to just measure the thickness (ie the 20cm in the above example, not the 40cm).

If you box is square (no curves) there's no problem

How did you measure the rocker?