Your code line
chklist.Remove(t);
is incorrect as it tries to remove the item
t
(which is an item in the
purchaseResult
list) from the
chklist
. As it is not part of the
chklist
it is not found and so nothing is removed.
To make your code work you need to remove the item that is in the
chklist
, which is just an alias for the
poRevice
list.
The code could look like this:
chklist.Remove(poRecive[counter]);
break;