Kevin Hart got payback on Nick Cannon.

The Fatherhood actor, 42, pulled off an epic prank on Cannon, 40, sharing a photo on Instagram Thursday of a billboard he got, broadcasting Cannon's cell phone number for everyone to see and a message soliciting parenting advice. The sign reads "For any advice on fatherhood? Call my best friend Nick Cannon."

Hart said he got billboards in Los Angeles, Atlanta and New York.

"Since my brother @nickcannon decided to buy me a lama for my B Day I decided to do something nice for him as well….Here is a digital billboard in Los Angeles….I also did some in ATL & NY," Hart captioned the post. "If u want any advice on fatherhood please call my BEST FRIEND @nickcannon ….I'm sure his phone has been ringing nonstop ???????????????????????? GOTCHA BACK BITCH #PRANKWARS."

On his Instagram Story, Cannon appeared to take calls from strangers who dialed the phone number, writing that his phone "won't stop ringing" and he "hates" Hart for it.

For Hart's birthday earlier this month, Cannon pranked him by purchasing him a llama. In a video on his Instagram at the time, Hart called it "childish" and showed the message Cannon sent with the gift: "Since I'm having all these new kids, I thought I would bless you with a new one as well. Save the drama for your llama. Happy birthday."

Cannon welcomed twins Zion Mixolydian and Zillion Heir with Abby De La Rosa on June 14. His son Zen, whom he shares with model Alyssa Scott, was born nine days after Zillion and Zion.

Additionally, Cannon welcomed daughter Powerful Queen back in December with Brittany Bell, with whom he also shares 4-year-old son Golden. Cannon is also dad to 10-year-old twins (son Moroccan and daughter Monroe) with ex-wife Mariah Carey.

On his Power 106 Los Angeles radio show earlier this month, Cannon said he has been "having these kids on purpose" after City Girls rapper JT advised him to "wrap it up," a nod to using a condom when having sex.

"I don't have no accident," he said at the time. "Trust me, there's a lot of people that I could've gotten pregnant that I didn't. ... The ones that got pregnant are the ones that were supposed to get pregnant."

Hart shares 9-month-old daughter Kaori Mai and son Kenzo Kash, 3½, with wife Eniko Hart, as well as son Hendrix, 13, and daughter Heaven, 16, with ex-wife Torrei Hart.