The quickness of so many resorting to calling something they haven't yet seen a hybrid helps illustrate the problem with hybrids even being in the hobby.
One person here has correctly identified it. CrazyCoolPeacocks, job well done!
The striping, solid double-stripes high on the body at a slightly angle, screams Chilotilapia. The head-shape gives it away as C. rhoadesii rather than C. euchilus (those are the only 2 Chilotilapia species). The head shape might appear off to some because it's such a young fish. FWIW, the fish pictured is a male and with such early color, he should look really nice as he gets older.
FWIW, if it had stripping on it at the time you bought it, that would have given it away as not being a peacock of any kind. It could have been a tank labeling error, and obviously the staff didn't know any better, but perhaps we can't expect everyone to know everything so I'm not sure how much I'd fault them unless they'd argued the fact that fish was a eureka jake.
