Floyd Mayweather & Shantel Jackson 'beef' intensifies: ex-fiancee's Instagram 'shut down,' jealous boxer 'owns' former girlfriend

Floyd Mayweather and Shantel Jackson are no longer engaged - and the legendary, undefeated boxer wants his ex-fiancee to know JUST how much she's missing out on now...

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Floyd Mayweather & Shantel Jackson split for good! Ex-fiancee 'moves on' after Instagram shutdown, 'upset' with break-up drama

And Mayweather's being pretty tough in his former flame! As Mstars previously reported:

Floyd Mayweather dumps Shantel Jackson, repo'd Bentley after cheating scandal?

Floyd Mayweather's ex-fiancee Shantel Jackson 'broke,' pawns expensive Birkin bag

Floyd Mayweather embarrasses Shantel Jackson, entourage tease about pawned Hermes purse

And now he's taken things to extremes - by deleting Jackson's Instagram!

At least that's what happened, according to the infamous gossip webloid MediaTakeOut.com.

And as several fans probably know - Jackson LOVES updating her Instagram account. Lately, she's been posting a slew of photos hanging with her supportive girlfriends.

So, she was forced to make a new account!

If fans click-on MissJackson's original Instagram, the page is no longer found. So, she's now "TheOnlyMissJackson."

Fighting words! Still, Jackson lost her over 200,000 followers.

As MTO points out:

"...Shantel never ACTUALLY owned the website. Floyd's team CREATED IT - and had her sign PAPERWORK that the Instagram account was MAYWEATHER PROPERTY."

Once Jackson began promoting some celebrity appearances on the account, Mayweather quickly shut it down. Ouch.

Looks like this bitter ex feud isn't about to simmer down anytime soon!