just a bug of his system
if u buy X,u can replace Y
X=1,Y=1
X=2,Y=2
X=3,Y=3
X=4,Y=1
X=5,Y=1
X=6,Y=1
X=7,Y=2
X=8,Y=2
X=9,Y=2
X=10,Y=3
...etc
30% of total and only 1 time per day
i buy about 50 pcs from him every day and sometime validity over 70% and sometimes under 70%
his support sometimes give...