then you do have them?怎么看不懂呢?

then you do have them?怎么看不懂呢?
原文如下:
"have you got any large paint brushes?" i asked the girl in the shop.
"i am sorry,"the girl said."we don't have any."
"have you sold out?"i asked.
"no"she answered.
"then you do have them."
"no,"she said,"we don't sell them.No one ever asks for them."
"well,i am asking for one."i said.
我想问:
第一,then you do have them.do当什么讲?
第二,no one ever asks for them.这句中ever当什么讲?
ever这词我是想把它理解为曾经,但是后面跟了一个asks为个表示一般现在时的词,总觉得ever和一般现在时连用有点矛盾,这句如果用完成时态我还可以理解,因为从过去开始到现在一直没人买过这种东西,所以这家商店才没有卖.