Oh, Debbie...I'm sorry...that's awful. I'm afraid to use my Visa ATM for purchases like this for just that reason -- if it gets overcharged on a credit card, at least it doesn't mess up your cash flow, no overdrafts, and you can dispute it with the credit card company.
I don't work for Disney, but I DO work in customer service, and I've taken escalated calls (requests for a manager) as a senior rep. This is what I would suggest.
Call Disney, tell them very politely and calmly that you have to speak to a supervisor.
The rep will probably say, well is there anything I can help you with first?
Tell them, well, this is a problem I've been trying to resolve for three days, and now it's become very very serious. I was told I would get a call back from a manager, but it hasn't happened and I can't wait any longer.
They will probably ask you to explain the situation -- go ahead, but tell them again, if you can't help me, then I really need to speak to a supervisor.
If the CM can't help you, try to say you will wait on hold for a supervisor because the situation is THAT urgent.
The key:
stay very calm, and very polite with the CM for the whole call. It's ok to convey how frustrated and how upset you are, but what happened is not THAT CM's fault. And it's very likely that whoever made the mistake -- it was just an honest mistake. But it's now very serious because you have no access to any of your money and you can't pay your mortgage. Disney should resolve this, acknowledge it is their mistake, and if necessary write a letter to your mortgage company explaining their mistake to see if any late fees can be waived.
Where I work, if we make a mistake and double charge a person's bank account (and it's rare, but it CAN happen), we will try to contact the bank to see if they are willing to reverse any NSF fees, etc. But individual companies or businesses might also charge bounce check fees, and we can't usually get those refunded. In that case, we at least try to offer the customer a credit on their account equal to any bounce check fees they incur due to our error.
I also agree, see if your bank will dispute the other charges as fraudulent. I don't know what a bank's policy is on that, because it's not the same as like a stolen credit card, but it's certainly worth asking. Especially if you can't get resolution from Disney in a timely manner.
Good luck, let us know what happens!
