When I had a student visa, I also ran around 6-7 different banks, but they all said I didn't have enough documents to open an account(The school said it was enough). In the end, I carried the documents with me every time I went out, and whenever I passed by a bank, I just walked in to try. Finally, on a very random shopping day when I was passing by the Kasikorn Bank branch in Siam Square, I succeeded. Thailand is a very interesting place - each branch of the same bank can have different hidden requirements.