At least the seller was being honest Norm. Many younger Chinese do seem to be taught English in school, but the level of competence varies a lot. Some have little grasp of it, others are fluent. I guess when we ask a question in English, if they don't know what we are talking about they have to go find someone else who can, and that person might not always be available. At least that person was being honest and not just replying with nonsense for the sake of providing a reply.
I remember back in high school being taught the only languages on offer: French or German. Neither have been much use to me, although German has helped on the few occasions when I have purchased Bosch parts from Germany. Nowadays we have the benefit of Google translator which is getting better all the time, so really there should never be any excuse for not understanding. Of course Google is forbidden in China, but you would think the State would provide translators to their immense work force? The trend in Australian schools has shifted towards mainly Asian languages these days, because that is where market forces have taken us, for good and for bad. Many Japanese can speak English today and I expect the trend to learn English in China will mean many Chinese people will be able to speak at least rudimentary English as the years go by.
I often get a laugh out of the way Chinese sellers call us "Friend" in their communications. Messages often begin with "Dear Friend" or "Hello Friend". I have now got into the custom of beginning any question to Chinese sellers with "Dear Friend". I guess it always pays to remain on such friendly terms with our major trading partners?