Product: Credit card

I opened a Checking/Savings with Bank of America in XX/XX/XXXX. To begin the process of creating good credit history, I opened a credit card with BoA in XX/XX/XXXX. Recently, I made the decision to leave the US for an extended period, while studying in the XXXX, and therefore, opted to close each of these accounts, with the help of the banking center clerk at the XXXX XXXX XXXX, NY branch. Having been previously advised on this matter by another clerk at this location, I explained my situation, and requested the precise amount of money first be transferred to pay off my last remaining credit card charges. I received the receipt for this transaction, as had been done previous times I used this process to make a credit card payment. I also received the email stating my payment had been posted. It was then explained that though I could withdraw my available money, I could not finalize closing of the accounts at the center that day due to a few pending transactions, which would likely clear in the following XXXX days. I was then further advised that the amount of money I requested to have withdrawn from my account, in order to close, exceeded the bank 's limit of in-stock cash. As such, the clerk withdrew as much as was allowed. Because I was scheduled to leave the States within the next few days, I tried another banking center I had been familiar with, the BoA in XXXX, NY. At this branch, the clerk advised the same, that the closure process for the accounts could not be initiated until a few days later when the pending transactions had cleared. As before, I completely understood, and we proceeded with the withdrawal process. In this case, I was told by the clerk attending to me that there was no per customer limit for withdrawals from closing accounts, so we proceeded as such, to withdraw the available funds. 
A few days later, when all transactions had cleared, I called to ensure my checking and savings accounts were closed. Within the week however, my credit card account was charged again, the amount I had paid, with an additional 'returned check ' fee. An email was sent saying I owed the bank the sum of money again. From my international location, when I called BoA 's credit card center, they stated that my account did not have the amount to cover the transaction. 
I was transferred to the checking/savings department, where upon checks with the clerk, I was told the item for having been put toward payment of the credit card had been stated as pending on my account at the time of the withdrawal ; there was a discrepancy in the internal system. A report was then filed on my behalf by XXXX of these agents, and I was told I would receive a follow up call from a supervisor within four days. To this effect, a case had been opened and I received a confirmatory email, as such. However, the next day, I received another email saying the case had been closed, despite no one contacting me and no reason was given as to the closure, but that I had to pay the money. 
Your assistance in resolving this matter will be greatly appreciated, as I am a student and no longer have that sum of funds easily accessible. I would further appreciate this being done as promptly as possible, as I have also been charged XXXX late fee ; another will negatively impact the credit score I have been trying to build while in the US.