I really wish I could give Thai Lahna more stars because of their location - the Arcadia area needs a good Thai place (enter Sa Bai?). I'd rather give them some advice, although based on their customer service, I don't think they are open to constructive criticism.
I went there regularly up until Valentine's Day in '06 when I was served raw fish in my seafood stew. They were super busy and the undercooked food would have been forgiveable if they acted like they cared, or offered to replace my meal, which they didn't. To further break the mood, our main waitress (possibly the manager) was extremely rude to the rest of the staff and was yelling in a very squeaky, high pitched voice from the dining room into the kitchen. I felt horribly embarrassed for all of them.
We decided to try it again - because of location. The service was not necessarily rude, but they weren't friendly and didn't make us feel like they welcomed our business. The food was too salty, completely masking the flavor of the dishes we ordered, and making me wonder if they salvage leftovers by re-cooking them and adding more salt (gross). The positive reviews on yelp regarding flavor are very curious to me. Then they acted like our request for take-home containers was an inconvenience.
With so many other restaurants in the area, including several Thai restaurants within 5 miles, we would much rather go somewhere with happy, nice employees and flavorful food.