Finally, when I did manage to book a machine, it took few minutes to figure out which washer/dryer I had booked, as the label on the machines were equally confusing.
The whole experience made me realize the importance of pictorial interfaces. Pictorial interfaces, with appropriate use of iconography, can cover various user demographics. Pictorial interfaces cross the language barrier and illiterate users will be able to understand them as well. Pictorial interfaces do have few drawbacks regarding accessibility (how will a visually impaired user use these systems?), but however makes things simpler.