I suspect that you actually want to say something along the lines of:
UPDATE tblsummaryIMPORT SET status = 'for payment' WHERE status=@status AND promocode LIKE '%without loan%'
Having a SELECT statement before the UPDATE does not restrict the records updated to those returned by the SELECT - the two operations are independent.
promocode LIKE 'for payment'
is exactly the same as
promocode = 'for payment'
as the search text contains no wild cards. '%' is the SQL wildcard for 'any number of any character' in the same way that '*' is for windows filenames