Sorry I dont have a 'good' outcome! I contacted csa 6 years ago when my youngest was born, they called me back about a month later and said they finally got in touch with FOB, but he was denying beign the father, so I told them taht he'd put his name on the birth certificate, so he must have thought he was then! They said they would get back in touch with him and if I'm happy wth it, tell him that he'll have to pay for a dna test.
So 6 months later, still heard nothing back, so I called them.. asked what was happeneding with my claim, they said they couldn't find any information, and would pass me to another department, after being on hold for an hour, someone answered, said they also couldn't find any information, and said they would have to pass me onto head office. Another hour on hold, and head office appear on the line, saying that all they can see is that my application was closed, but couldn't find the reason for this! I dont know about now, but back then they weren't allowed to close an applicatio without informing you of the reason, in writing, which they didn't do. So this head office lady said she's have a search for the reason, put me on hold for half an hour, then came back saying she would have to go to an even higher department to find a reason for it being closed, and that she would call me back in half an hour.
I'm STILL waiting for her to call me back, 6 years later. I spent the next year calling them up every now and again, asking why no one had called me back.. but just kept going through the same thing, getting passed up to higher and higher departments, put on hold, and saying again, someone will call me back. In the end I gave up, and didn't know who/where could go to with help dealing with them!
Basically I think FOB refused to pay for a dna test, and they just couldn't be bothered to push the matter. I hope things with csa have changed now, coz im about to go through it all over again
I hope you finally have more luck than I did!