Sorry for any confusion around the text messages you've received. As you had placed an order I'd be inclined to believe these messages are genuine, although I can understand your concerns with that not being very apparent and the messages just coming from a mobile number. It's always best to err on the side of caution if you're unsure.
May I ask what you had ordered? I'd be happy to take a look into it and see if we can see any related notes on your account to try & shed some light on this. Just get back to me via PM and we'll take it from there.