I've reached the point where I just have to laugh.
Very simple one page finance summary to accompany consent order application.
He got 3 numbers wrong. (there's only about 10 and some of those are subtotals)
He send me a photo of the redone form to check before sending to solicitor (what am I? Your wife?!
)
All 3 incorrect numbers were corrected with new incorrect numbers. Plus one if the incorrect correction through up a fourth error in the first attempt 
So I told him the right answers, and off it goes to solicitor. Who now tells me that he didn't sign it.
Yes, he could be stalling to take the piss, but actually I think he's just a dumbfuck.
Thank goodness we're divorced!