Kitten help Please Help?!?

i have a tiny kitten that i found in the street infront of my house, hes about 3 weeks old. All today i've been waiting for his mom all day today but she hasnt come back &the lil kitten kept cryin & cryin but she never came back..i tryed giving him replacement milk with a newborn kitten bottle but he wont take it..i have been trying to call his mom with some food but just havent seen her & i know the kitten is hungry. What should i do? i dont want him to die because i know he misses his mom. but i dont know where the hell she is?? How can i make him eat? or wat can i do? i need help!! :(