i'm so embarassed.....

So i had an appointment today w/a vendor in Brooklyn. Well i leave my apartment (i live in camden, nj---2 miles outside of philly) and i go to an ATM to take out money so that I can pay for tolls. Well, i try to take out 40 dollars but the machine starts making funny noises, then it proceeds to say 'sorry, your transaction has been canceled. This machine is temporarily out of service.' I think to myself FART! Now i have to go to another ATM. Well it prints my receipt and shows that it deducted 40 dollars in my account (I only had 40 dollars in my account). So i drive to another ATM, thinking okay this must be a mistake, and when i try to take 40 dollars out the machine says 'sorry but youve exceeded your balance'!!!! So i call the bank and i explain the situation and they tell me that I cant do anything until the transaction posts which would not happen until tonight, and then i would have to file a dispute to get the money back. So basically i had to cancel the appointment because i had no money to get there!! I felt so embarassed having to leave a message w/the vendor telling them all this. I feel like they probably think it's the lamest excuse. I even tried to somewhat ameliorate the fact that i didnt have money in my account by saying that im a law student that's why i have no cash...but i felt so utterly ridiculous and poor!!