Apollo Nida Insists Phaedra's Divorce Docs Are Invalid

Apollo Nida refuses to accept his divorce from Phaedra Parks is a done deal, and his reason -- spelling counts.

Apollo points out his ex's legal name is Phaedra Parks Nida, but in her divorce docs it's spelled "Nita" -- ditto for the spelling of his name in those docs.

He's now filed a motion to vacate her divorce, but not only due to the typos. In the motion, obtained by TMZ, Apollo says the 'RHOA' star took advantage of the fact he's in prison. He says there was a final hearing in July, but he was never notified of it ... and therefore, the divorce should be thrown out.

TMZ broke the story ... Phaedra's unsealed docs appear to back her claim she's been single since July, but if a judge buys Apollo's side of the story ... they could be back to square one.

Let's not forget ... Apollo filed his own divorce docs.