My friend visited Nha Trang for Tet, and had confirmed her bus reservations a full month in advance (Lien Hung bus lines). She had even called the morning of the return trip to re-confirm and was told 'no problem'. But at the start of her return trip, the company first allowed her on the bus. Then summoned her to the ticket office for some "information". The "information" was that they had a large party that needed her seat and they were changing her reservation to the next day... and while they were explaining this, the bus left (snuck out?) the station without her. The particular route she was taking (Nha Trang to Ca Mau) runs once a day. She had no option but to stay an extra day in this overcrowded vacation city. We don't know yet whether they will actually honor her "revised" ticket tomorrow.
But thus truly raises the question: why get a reservation if the company can cancel at the last moment?
We urge all expats to avoid Lien Hung Bus at the risk of having your own reservation cancelled.