Honesty is always the best policy.
Tell your bank your account is cleared, you may have had it paid for by a family member, but can't honestly recall.
Ask them to check that everything is OK, and on confirmation, close your account if you wish.
One thing is for sure - if the account is not paid, or has been paid by improper means, the bank will find out, so you need to get them on your side from the start.
This kind of thing happens more often than yiou would think, loads of people are lousy at managing their finaces, so they won;t be too upset at your query.
However, treating them as fools, which they are patently lot, means potential co-operation and understanding evaporates very quickly.
Have a chat - sort it out, you'll be glad you did.