As a bilingual Thai-English speaker, I previously complained and warned this company about two of their "Thai" interpreters not actually speaking Thai as they had contracted them out to organizations assisting a Thai friend of mine, and twice I was told how seriously the company takes it. However, my own daughter who was recently adopted from Thailand, was being evaluated for something related to school and I could not be her interpreter, and twice this company offered both of these Laos men, who have no formal training in Thai and don't actually speak Thai. Thankfully, we caught it the first time and didn't waste our time, but the second time we didn't catch it until we were face to face with the interpreter and heard him speak because the evaluator had been promised a native Thai speaker. My daughter's name is basic as basic can be for Thais, and the man couldn't even pronounce it, meanwhile my daughter couldn't understand his basic introductions. The company charges $85/hour + cost of transportation in most cases for Thai interpreters, and this is the kind of service they provide.
Their assessment test of potential interpreters' language proficiency previously involved the individual listening to English and interpreting it into the other language, and then listening to themselves and interpreting it back into English, with no proven native speakers of that language listening, and clearly this is not fault proof for more unique languages where no one actually confirms accuracy in the non-English language vs the potential interpreter just understanding themselves.