I read somewhere else that 'da' means a non fixed location, such as someone pointing to a spot on the ground and saying "Mein Hut ist da!" whereas 'dort' is a fixed location eg. saying "Sie arbeitet dort." instead of saying "Sie arbeitet in der Bank."
Da is also distinguished from dort in that is closer in distance. In fact, da can be so close that it's no longer there, but hier. Per wiktionary (http://en.wiktionary.org/wiki/dort#German), dort is more formal, rarely heard, esp. in north & west of Germany.
Es gibt kein dort da?
Hello. I think (not native speaker) that "dort" always means "there" while "hier" always means "here", but "da" can mean either one depending on the locale. Duo teaches that "da" = "there", but I think that it means "here" in some places though, so I guess "da" is just a bit more general way to refer to something nearby.
Is "Konto" used specifically for bank accounts, or can it refer to other types of accounts?
"I have an account there" was marked as incorrect - shouldn't it be accepted, as it's obvious that I mean my account?
Mein Konto means you have one account and that one is there, an account could mean you have more and one happens to be there. Picky but that might be why it's considered wrong.