I have been using acrylic disk for few months. I have notice that my cakes are still frozen after the client get there cake. I bake and freeze my cakes im the early week. And decorating and place in the freeze the day before or early that morning

What am I’m doing wrong ?

You place them back in the freezer when they are decorated? Or in the refrigerator? If you put them back in to the freezer, that is why they are still frozen. After being frozen, they need time to come back to room temperature. I freeze my cakes before decorating, but place in the fridge if they have perishable filling, or for about 1 hour to chill for transport, but I never put them in the freezer after decorating, if I am understanding correctly.

Example 

i bake and freeze my cakes on Wednesday and frost the cake with disk the night before the cake is due the night before and place back in the freezer until I decorating the cake. 

Am I’m doing some wrong 

Personally, I wouldn't put it back in the freezer. There isn't a need for it to go back in there once you have iced it. If there are no fillings in it that would need to be refrigerated, like cream cheese, fruit. etc, you can leave it on the counter until ready to decorate.

I agree with ypierce.  It isn't like you are icing the cake a week or more before the cake is due.  You are icing it the night before and then decorating the day of so I really don't see the need to put it back into the freezer.

So after I frosting the cake with the disk. How long should I keep in the freezer to get the sharp edge 

I've never worked with the discs, but an hour or half an hour should get it firm, but not frozen through.