18-year-old Junior Gibbons says he was at a Target in Sandy Springs, GA on Monday when he saw the rapper buying a baby stroller. Gibbons took out his phone to record a selfie video, but when he asked, “What up, Offset?” … he didn’t get the response he wanted.

Instead, he says he ended up with a cracked phone.

After his phone slammed to the ground, Junior claims Offset told him to get that “f***in’ phone out of my face” … and then walked out of the store.

Junior tells us he went to the cops and filed a police report Friday, but says his family just wants Offset to pay to replace the phone.