i sent my cellphone for repairs and haven't got it

i bought a phone a month back then after three days it was faulty i then took it back ,then was told i can't exchange it coz i lost the box of which i understood that .....when i went to ask about the phone i was told thy don't know where the bookings book is ,and they will call till now there is no call from them .....now i don't know who to talk to all i get is excuses..i am not happy about it,,,,,,i booked my phone on 15th of December ,its either i get my money or my phone