God's Promises

I've been thinking recently "does God change his promises?" - that may seem like a simple answer to some of you. It's not like God is all of a sudden going to say... "hey guys, I've changed my mind about never flooding the earth again, here's some armbands - good luck!!". That of course refers to God's promise after flooding the earth when Noah and his cru built a kick ass boat to survive. He (God) hasn't flooded the whole earth since and I fully believe that he won't. I've had promises made to me by God, or at least I think I have. God promised me that I'd be on CYM, he promised me that I'd go to Luton - something I hated the idea of. He's also promised me other stuff which involves other people or involves future possible working opportunities. Both of which would be unfair to go into on here. One of those though seems to have been taken away. The fulfillment of the promise will not happen. There's a few answers to how that this can be...

1. God changed his mind - already proved that one wrong me thinks!
2. I misheard God - that could well be true, G speaks loud enough for anyone to hear, I just didnt open my ears perhaps. Maybe that's what it was.
3. The promise was a two way thing, which I broke by messing up - again, that could be true. I certainly have let God down, but would that be enough to break a promise? Surely grace would help there? And as long as I'm sorry - which I flippin am!
4. The promise still exists, I'm just ignoring it or don't believe it can happen - hmmm, maybe.

Your thoughts please... (not necessarily on the comments page, maybe an email, or phone or coffee or a meal, if you pay)