Got a reply from XNet stating
"We can assure you that in both cases neither will have any effect upon data billing as firstly local data is not chargeable, and secondly the total amount of standard data is still correct despite the delay in its recording."
For us we normally sit around 10Gb "billable" / mth ... and this month we are are 26Gb with 10Gb of local!!!
At the moment our line is throttled, with Billable data at 26Gb .... and our limited adjusted to 30Gb ... so stuffed if I know what is going on.
Going to be slacked if I get billed for this ... as with 3 years of historical usage data ... have never got anywher near this ... except when we did 20Gb one month when I was downloading all my MS Action Pack software.
Xnet seem to be holding the line that Standard Traffic is accurate and will be billed ... but local traffic is incorrect and is being worked on. For me, that doesnt line up.