She couldn't have been legally served divorce papers without them being filed first. I haven't read any of the replies so i'm just telling you what I have to say. Lol sorry if I repeat questions.
So... He served the papers to her (himself) and she ripped them up? If so, they have no legal standing.
Ok. I just went back and read your reply...
I still don't understand how papers were served but no filed. Either way, it's irrelevant. Just because she filed and is going for custody, that means nothing. People think they have the advantage because they filed first, and in all honestly, it's simply not true.
As for the receipts... There's nothing you can do about that. In court, he will be given the option to testify (which can be helpful or detrimental, depending on the case). It may be advantageous for him to testify that he provided for them, but if he has no proof, maybe let the lawyer speak for him.
As for you living with his parents... Is there *any* way that you can get out on your own and provide a place for the children to stay for visitation? Also what are the particular reasons that you're staying with his parents? The courst may offer him a stipulated amound of time to get on his feet and provide a place for his children to stay. If he doesn't abide in the set amount of time, there will have to be another court hearing.
As far as the mother leaving the kids with her parents... You would think that that in and of itself would be a red flag. Unfortunately in the courts system, you can't really prove if she's working/etc during that time, or if she's even actually leaving the kids there unless it's an actually babysitter that documents their time there. That doesn't help you much.
The mold and unsafe living conditions... You may have a slight chance. She's putting her children in danger, which is much more detrimental than staying with daddy and his parents.
I don't know... The court system is so inconsistent. It really just depends on the judge.
I wish the best of luck to you. Feel free to pm me if you think I can help you further.