Dial plan for tool free number

[drhilbert00]

Dear friends,
there is something very strange happening with my dial plan. I'm dial plan I have this specific entry for forwarding italian tool free number to a suitable VoIP provider that can handle it.

The dial plan rule is the following:

_8[04][0-9]X.

this is becasue tool free numbers in Italy begin with 8 and it is followed by either 0 or 4. In principle the [0-9] shouldn't be needed but it has to work anyway.

If I test the dial plan using for example 803380 (Italian Internet provider) it works perfectly, but with 800877877 (Italian UPS service) the call is forwarded to sip:800877877@public.sip.magrathea.net and public.sip.magrathea.net is not one of my provider!!!! What's wrong?

Can you help me?

Cheers,

drhilbert