How to purchase Train Ticket in Beijing?

It`s gonna take a bit long, hope you don`t get bored reading it :-)

How to purchase Train tickets in Beijing ? I Know there are several kiosks around the city (in fact, there is one near my house) but apparantelly they don`t sell ticket to all destinations, e.g I went there yesterday wanted to buy return train ticket to go to Beidahe this Saturday and I was told that they don`t have that ticket there and I have to go to Beijing Train Station. So, I went this morning to Beijing Train Station and went to the ticket counter written "ticket counter for foreigner only". The ticketing staff didn`t speak english at all (not even little bit) and there were still many local people queing in that counter, so what is the purpose to have this counter, isn`t it ? Not all foreigners/tourists are able to speak mandarin, I speak mandarin my self, not fluently but more than enough to understand daily life conversations but still I couldn`t understand the ticketing staff because she spoke very fast :-(. Fortunatelly I took my ayi with me so she spoke with her and succeded to purchase the tickets :-).

I also found several websites stating they can provide online train ticket booking e.g Protected content (in chinese only, my ayi helped me to check the schedule first but when I wanted to book the ticket something wrong with their website), the other website is Protected content , but I have to have Protected content first before able to book train ticket from them (???), the other website is even funnier, they reply later on informing that they don`t provide the train ticket online booking service anymore (so why they still display it in their website ??)

I don`t mind if I have to pay a bit higher as long as I can avoid wasting my times Protected content only for going to the Train station to buy the ticket. So, can you share your experiences while purchasing train ticket in Beijing (or China in general) ? I plan to explore few cities in china by train later.

PS : One saturday couple months ago, me and my husband wanted to explore Tianjin so we just went in the morning to Beijing South Railway Station and purchased return tickets that were available at that time. Thinking back about it and comparing with my recent experience, I think we were so lucky at that time to have the tickets :-)