Kevin Hart and Nick Cannon are in the midst of a full-fledged prank war. Earlier this month, Cannon sent a llama to Hart for his 42nd birthday. He shared a video of the “Wild N’ Out” host’s gift on Instagram with a caption that read: “Nick Cannon has to be one of the biggest assholes on the planet.”

The comedian got his revenge recently by purchasing digital billboards throughout Los Angeles, Atlanta and New York City with the message, “For any advice on fatherhood? Call my best friend Nick Cannon.” Beneath that in a smaller font it reads “Hey guys! Here is his cell # 323-509–0988.”

Hart was making light of Cannon’s 5th, 6th and 7th child all being born last month. On Instagram, Hart shared a photo of the billboard with the caption, “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….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.”

The phone number Hart shared actually belongs to Cannon. And surprisingly, the multi-talented entertainer has been answering some of the calls. In an IG Story, Cannon commented that he’s picked up at least 20 calls from fans, including international ones from Zimbabwe and Nigeria. “Look at that. It’s coming in double numbers at a time. It just won’t stop ringing, and now there’s a white screen,” Cannon said. “My phone is ruined!” Cannon called his “Real Husbands of Hollywood” co-star “pretty shitty” for the prank, and said he would get him back someday.

Check out the billboard below and feel free to give Nick Cannon a call: