I'm not sure if my maths is wrong, but it looks like something may be up
with Vodafone's billing system.

My unbilled usage reports this info:

Last Call: 12:32 22 Dec
Amount unbilled £1.26
Minutes used: 211.47
SMS sent: 31
GPRS used: 9.464MB

(I got this by dialling 44555, which, interestingly has a different
response from a friend's Vodafone, and a different format SMS detailing
MMS, but not GPRS).

The odd thing is the unbilled charge. I had 50-odd minutes rolling over
from last month, according to Vodafone's website, so I've 250 to use on
my 200 mins + 250 text package, so the charge is not from voice calls.
The website confirms it is data I've been charged for after about the
17th Dec. My 250 text package is equivalent to about 12.77MB of data
(250 texts at 12p is £30, and this can be used by text messages at 12p
each or £2.35/MB of data).

Using SMS sent and data usage I get:

31*0.12 + 9.464*2.35 = £25.96

which means I'm still £4.04 away from my limit of £30. The breakdown on
the web matches the totals, yet I've one WAP entry listed as partially
bundled, but 3 later entries in time as being fully bundled. Thereafter
I start getting charged. The amount unbilled is the sum of all these
charges. This is the breakdown of the bit of the bill where the charging
starts. At this point I've used about 8.80 MB.

Dec/17/2006/22:10:46/Data/INTERNET/5KB/229BT/GBP/0.000/In/bundle
Dec/17/2006/22:22:24/Data/INTERNET/2KB/676BT/GBP/0.000/In/bundle
Dec/17/2006/23:05:23/Data/INTERNET/17KB/75BT/GBP/0.000/In/bundle
Dec/17/2006/23:16:39/Data/WAP/139KB/354BT/GBP/0.000/In/bundle
Dec/17/2006/23:23:01/Data/INTERNET/9KB/573BT/GBP/0.000/In/bundle
Dec/17/2006/23:32:46/Data/WAP/40KB/336BT/GBP/0.012/Partiallybundled
Dec/17/2006/23:34:38/Data/INTERNET/2KB/891BT/GBP/0.000/In/bundle
Dec/17/2006/23:47:08/Data/INTERNET/2KB/600BT/GBP/0.000/In/bundle
Dec/18/2006/13:32:57/Data/INTERNET/1KB/25BT/GBP/0.000/In/bundle
Dec/18/2006/14:51:20/Data/WAP/33KB/853BT/GBP/0.067/
Dec/18/2006/15:13:16/Data/INTERNET/1KB/943BT/GBP/0.004/
Dec/18/2006/15:13:55/Data/INTERNET/56KB/549BT/GBP/0.111/
Dec/18/2006/15:31:07/Data/INTERNET/14KB/144BT/GBP/0.028/
Dec/18/2006/15:31:29/Data/INTERNET/811/BT/GBP/0.002/
Dec/18/2006/15:31:51/Data/INTERNET/6KB/284BT/GBP/0.013/
Dec/18/2006/17:29:17/Data/INTERNET/2KB/691BT/GBP/0.006/
Dec/18/2006/17:43:30/Data/WAP/289KB/51BT/GBP/0.565/
Dec/18/2006/17:53:32/Data/INTERNET/65KB/35BT/GBP/0.128/
Dec/18/2006/18:38:53/Data/INTERNET/74KB/883BT/GBP/0.147/
Dec/18/2006/20:16:44/Data/WAP/68KB/565BT/GBP/0.134/

Any ideas? Between getting a 44555 report at lunchtime, and again this
evening, the GPRS data seems to have changed (it is including more data
now than earlier today) so maybe Vodafone are doing something to the
billing systems today?

Mark.