Please note that 5asec is what we in the UK would regard as a dry cleaners. Such places are often found in shopping centres/malls. They do however also wash shirts and blouses, and iron them. They won't however do general laundry as far as I know, and are nothing like Dot Cotton on Eastenders...
I've used 5 รก sec and found them expensive and less effective than traditional Polish ones. Some of the old ones look old-fashioned but generally give a better service.