Unable To Delete Old ZIP Files Using Maintenance Plan

I'm using below script within the execute T-SQL statement task of the maintenance plan, which is created to delete the zip files older than 2 days, the task runs before the backup database task gets kicked off, but some how the task is not deleting the old .zip files.

Code being used within the task: output of the @delete_file variable within the delete command is Del X:SQLBackup*2015_05_06*.zip before it is passed to the final exec statement, the server is in EST time zone.

declare @ConvertDate char(10)
declare @Delete_file varchar(80)
set @ConvertDate = CONVERT ( char(10) , dateadd( dd, -2, getdate()) , 121 )

[code]....