For those contemplating booking online bus tickets with the Austrian company, Westbus, this is my experience.
In the middle of March 2013 I booked 2 one-way tickets for my sister and I to travel from Vienna to Prague with Westbus. All went well with the credit card and in a few hours the correct tickets arrived by email. On the front of the tickets is written on the left "Westbus" and on the right "Blaguss". It appears that Blaguss is the charter bus company affiliated with Westbus to travel this route.
One day later I checked my Visa credit card bill online and found that the two tickets had been charged not only by Westbus, but by Blaguss also. That is, the 2 one-way tickets were charged by Westbus and the same 2 tickets were charged by Blaguss.
I immediately sent an email to the customer service at Westbus, but there was no reply. I emailed 2 more times - no replies. I would have also contacted Blaguss but their website does not have an English option, as far as I could see. Besides, I figured it's a Westbus problem in that Blaguss got my credit card info from Westbus.
After one week of no response I called Westbus, Austria from Australia. (Although I skype and use apps to correspond with friends in Europe I don't have a cheap phone plan so it was very expensive). The woman who answered the phone at Westbus could see there was a problem and said she would do her best to get it resolved.
In the emails which followed, Westbus was given the reference number from the credit card bill for both the Westbus billing and the repeat billing from Blaguss. Then the Westbus rep said that Blaguss couldn't see a problem and could they please have a screenshot from my Visa online bill to see for themselves. This was sent. So now they have all reference numbers, dates, ticket info, and a screenshot of both the Westbus and Blaguss credit charge, adjacent to each on the statement.
Result? Nothing. The finance dept at Blaguss told the Westbus rep that there is nothing they will do.
Now I've had to initiate a Visa dispute resolution. Visa has copies of the actual tickets etc as well as their own record from the two companies, and I hope to have one of the charges credited eventually.
Finally: our plans were to travel to Prague by bus and return by train. However, when I went to book the train for the first week of May, all the 2nd class tickets for the times we wanted to travel were booked out.
So...back to a bus. We couldn't risk another Westbus fiasco, so I looked at Student Agency. Their booking process is a bit convoluted - you email them when you want to go and they email back with details on availability and how to book. It seemed quite ok. However, I needed instant results so I went through Eurolines, and successfully booked our return for the time we wanted.
The tickets arrived by email instantly.
The credit card has not been charged yet, but I'll be watching like a hawk.
Hope this helps other travelers be on the alert.