SSRS Report not using passed parameters; Uses embedded parameters instead

I have a report that takes a start date and end date as parameters. In the data tab of Business Intelligence Studio (visual studio), I have the following:

declare @start datetime
declare @end datetime

set @start = '2011-04-06T12:00:00'
set @end = '2013-04-06T12:00:00'

EXEC rpt_ExpiredQuickLook @start, @end

When I run the report on the report server and pass it different date parameters (let's say 2013 to 2014), I still get the ones I had in visual studio. Is there a setting in the report somewhere to use the passed parameters over the ones embedded? On the report server, I have the Prompt User checkbox checked under the report settings.

I have other reports that I created in the past that don't have this problem, so I'm super confused.