My phone is still redirected to PBXES after deleting the Trunk record

I filled in the trunk information of my sip provider because I wanted to test PBXES, but as setting up is quite complicated I deleted the trunk again because I have no time for this at the moment.
Unfortunately now my normal sip is not working anymore, because all calls to my sip provider (budgetphone) obviously still are redirected to pbxes.com.

example:
Time Caller ID Number Destination Trunk Context
18:49:24 "062??????" > s sip1.budgetphone.nl group-all

At first I wanted to delete my PBXES account completely but as this looks like a bug I am afraid to so because the trunk record might stay in the digital heaven forever, which could make it impossible to get my phone back to my normal sip provider.

So how can I reset my phone to budgetphone again?