Last weekend I was shopping in GAP and there was a funky tune playing - I'd never heard it before, and it sounded like it could be Bruno Mars.
It was quite upbeat and had the words "mercy, mercy, mercy, mercy mercy". Or it could be "merci, merci, merci, merci, merci" 
Having searched it's not any of the following;
Mercy, Mercy, Mercy by Queen Latifah:
Mercy by Kanye West
Mercy Mercy Me by Marvin Gaye (or Robert Palmer) - but it could, maybe, be a remix
Mercy by Duffy
Mercy Mercy by Jeff Lynne
Merccy by Bkay & Kazz
If it was being played in Gap, it can't be that obscure!