Complaint about unfair treatment by Standard bank regarding their business account bank fees I couldn't afford to pay

I had a business account with Standard Bank back 2014 and I have been paying bank fees and all that, then came 2020 with the pandemic and I became unemployed and business was not doing well so I couldn't afford them anymore so I made arrangements to pay R100 monthly which I did for several months and things became worse and I couldn't afford it any more, so they closed my account which I was fine with it, this morning I got an email from Maodi Attorneys telling about settling the debt with Standard bank and them taking legal action against me, like for real, I didn't take a loan with Standard Bank to begin with, this was a business account, so why am I being threatened with legal action and blacklisting? I'm not happy at all, why legal actions, can I be assisted on what to do and what are my rights as a consumer?