I don't know for sure, but I believe that the differences in the amounts that you can take out depend on the ATM/Branch you are using since the limits on BOFA debit cards is $500 per day. Did you try calling bofa or talking to somebody at the Scotia branch?
My suggestion for you is to use checks instead of your bofa debit card at an ATM. It seems from your case that your family deposits money into your debit account in the US and then you withdraw it at ATMs in DR, and by doing so you get fees charged every time you take out cash. If you wrote yourself checks from that checking account, you could deposit them into your own checking account at a branch in DR for what may be a lower fee/or no fee and no limits on how much cash you are getting since you will be depositing checks into the DR account and then withdrawing cash with your DR account debit card. Find out and let me if this works for you.