He sent a message to my phone and now he is saying he did not?

Ok this is going to be hard to explain but hear goes. My boyfriend sometimes works nights with his job and most nights he rings me, on this night which was only Saturday the 14 of August I said I might go down and see him when he was on his break.

However I did not go down but I did ring him, whilst speaking to him I recieved a text message as my phone beeps when I get a message I did not think anything of this untill we finished speaking and I read the text.

The text read, "I will contact you as soon as possible",as you can imagine I was somewhat confused at this point, I tried straight away to call him back and ask what did he mean but he didnt answer as he must have started work by then.

So I waited for two hours untill he returned home. I did not mention the text right away and every thing was fine I guess he thought he sent it to the right number.

So I said oh I have a text message have you texted me, he said no I havent touched my phone all day.

So I showed him the text with his name above it, and also checked his phone and the message was still in his sent box.

He still says he did not send this message but please phones can not write and send messages all by them selves so why on earth is the still lying to me he must think I am stupid or something and everyone has come to the same conclusion this just cant happen with phones.

After I had confronted him he went like a mad man very defensive and he started chucking things around which hes done before but not over this.

He got his car keys and went out which he had never done before. I am really confused about all of this why doesnt he just tell me the truth?

He is not eating as well as he used to, acting out of character forgetting what he has said to me things like this, which says to me that he has something on his mind.

Any Ideas anyone? Any advice would be great as I dont know what to do next.