Billy Ray Cyrus Fires Back at Estranged Wife After Abuse Allegations

Billy Ray Cyrus is firing back at his estranged wife after she claimed he bailed on their marriage one day before a planned double mastectomy ... but he has his own version of events.

The country star filed new legal docs in response to Firerose's complaint in their ongoing divorce case -- which Billy kickstarted by seeking an annulment following just 7 months as man and wife ... with BRC alleging marital misconduct as his primary reason.

Now, we're getting more of a sense of what set Billy off -- and according to his latest filing, obtained by TMZ, he's claiming Firerose completely misled him about who she really was.

Billy claims Firerose didn't tell him her real last name when they first met -- alleging she presented herself as having the maiden name "Hodges" ... when in reality, he claims, she had a completely different legal surname from a previous marriage, which he says she failed to disclose.

In the docs ... Billy explains that he started to become suspicious about his wife and her background when he started to pick up hints that she actually had a different surname -- which he claims was ultimately confirmed when his attorneys tracked down her previous divorce in California, at which point ... Billy claims he threw in the towel, feeling betrayed.

What's more ... Billy claims Firerose isolated him from his family -- including one specific daughter whom he doesn't name -- while going on to allege she inserted himself into his personal affairs with nefarious intentions ... namely, trying to use his last name to bolster her music career.

Mind you ... this is all in response to Firerose's own allegations about what she says happened leading up to his divorce filing -- long story short, she alleged Billy Ray left her high and dry after she realized she required a preventative double mastectomy.

Firerose claims that once she told Billy about this, he started to change and get incredibly hostile toward her ... alleging he'd insult her, and subjected her to verbal and emotional abuse -- all because she was pursuing a procedure her doctors said she needed. She also claims she was under the impression Billy would pay for this ... but says the rug got pulled out from under her with his divorce filing -- which she says left her scrambling financially, etc.

We broke the story ... BRC ran to court in May seeking to scrap his marriage entirely from Firerose -- and while he cited marital misconduct then ... he didn't clarify what it was over.

Remember, Billy Ray and Firerose have already unfollowed each other -- and now, they're trading allegations in court. One last thing -- Billy's attorneys Rose Palermo and Jason Talley tell TMZ they have evidence of a note and text message they say Firerose recently left and sent Billy, asking for him back, which they feel clears his name on the abuse allegations she's hurled at him.