Provider does not unregister

[xisdn]

Hello,

I have some providers that are registered with voxalot, after setting the "register" flag to NO the provider does not unregister (even after hours) calls still end up to the voxalot account.
Tried deleting the provider from the providers list but the provider is still registered with voxalot instead od being offline.

Thanks for your help,
Sandro

P.S. the provider is messagenet.it