Even though it's a Thai number it would still need to have the international country code prefixed for anyone in Thailand to call or message the number. As the banks only facilitate in-country Thai numbers it won't work. Only option is the send someone into bank.
You will really struggle to open a bank account without the correct visas nowadays, they have cracked down recently. You could use an agent to get one, it's not something I would do personally, but many people do.