the sister of murdered hairdresser said her sibling visited several women 's shelters every day but was refused a room .
leila alavi was found in dead in a car at a sydney shopping centre carpark .
she was working when she reportedly received a phone call and left .
a colleague found the 26-year-old stabbed to death on saturday morning .
court papers allege she was killed with a pair of scissors .
her estranged husband was charged with murder and refused bail .