1st dynamite....thats calledcarma , your ex has probably got your...LUG wrench and is hiding down a dark alley near your home, ready to slacken his nuts.
2nd sounds like either somethings stuck in the barrell or the wafers have collapsed inside, does it fit the boot, passenger door ,ignition ok ? if so then it'll just be that barrell thats stuffed, depending on make depends where you could get 1 from, you make even be able to get it re-tumbled to suit your key to avoid having a key just for that door, although this would obviously be more expensive. if it doesnt open any of the doors then it could be the key itself, a master locksmith would be able to compensate for any errors on your key when cutting a new one, if he cant then he shouldn't be a master locksmith.don't get a mobile one try to get down to his shop(mast. l/smiths have to have premises) finally if looking in the phone book then beware of all the scumbag callcentres who will invariably send round some subby who'll overcharge you and probably not sort things out, although he may get the vehicle open for you. this is an area i do know about although i deal mainly with house locks (not an ad by the way just giving advice.....for free)