Dialplan problem, UK 0800 numbers

[The King]

Hi,

I have my dialplans set as follows;

1 _01. +44${EXTEN:1} VoipCheap Yes [Edit] [Delete]
2 _02. +44${EXTEN:1} VoipCheap Yes [Edit] [Delete]
3 _07. +44${EXTEN:1} VoipCheap Yes [Edit] [Delete]
4 _080. 0044${EXTEN:1} Sipgate Yes [Edit] [Delete]
5 _00. ${EXTEN} VoipCheap Yes [Edit] [Delete]


When I dial an 0800 number I expect it to divert to sipgate, i.e; to
0044800xxxxxx@sipgate.co.uk

This wasn't working on my ATA or softphone, so I tried the 'test' in the dialplan settings, and instead it says;

A call to:0800500600 will get forwarded to sip:800500600@public.sip.magrathea.net

I have no idea who "public.sip.magrathea.net" is.
I have no such settings on my account, I do not understand!