ABSA WORST BANK EVER

I opened a ABSA bank account this year and I did not choose to have an overdraft, now I am in a minus with my account. Lawyers are calling me and telling me I have an overdraft. because I am using it. Since I opened that account it has been a struggle, I do not have a pin so how am I using the account. THE WORST BANK EVER TO BANK WITH and then the lawyers (Shapiro Shaik) want to threaten me and cannot answer simple questions.