I WOULD call those other Day Cares for another "chance". If they are good people they will welcome you with open arms. All you need to do is let them know you may have made a mistake at choosing a proper provider....if they have any reasonable understanding they will do just that...understand and give you a second interview.(who knows, they may have thought they lost a "good one" when you called to say, you were going somewhere else) You are not the only parent who has to make a few moves before finding the right Day Care. You live and learn, and hopefully with the next one you will know MORE of what to look for, doesn't mean you won't hit a road block or two but you should be better off because of this situation.
Good for you for giving this woman the chance to finish her contract with your son....says a lot about your charactor. I do believe that he is not in "poor" care, otherwise you wouldn't have chosen her in the first place...things just didn't pan out as expected (on both your parts) but it is really great that you and her can work things out for the next few weeks.
Sometimes it really does just boil down to "not a good fit", IF she really doesn't have a job lined up, I do have to say "shame on her"....never lie! doesn't get you anywhere, she should have just come out and told you things weren't working out! (if thats the truth)
I have to add though, although you could have a great outcome with a "new" provider the next time around, I do put myself in others shoes (and in your shoes) I would go for a provider who shares the same beliefs as you, understands you when you talk, you agree with ALL her rules and regulations, of course...you have a "good feeling" about, AND last but not least...due to the fact that you are "new" to Day Care as well....I would look for a Provider who has done care for a while, someone who has alot of families "under their belt" (maybe you can ask for references) and always look for OPEN and HONEST. Good Luck in your search.
ps. ultimately you can view this as a learning experience rather than a "mistake". The more you experience the more you learn!!!!