No communication or statement for 2 years 3 months

I had an account with Cell C that I terminated in 2020 July. The last statement that I received from them was in July 2020. Nothing received since then, 2 years 3 months later I get calls from their debt collectors demanding me to pay the outstanding balance with their levies. Why did i not receive a closing statement in August 2020? Is this how Cellc conducts their business? I have news for them, I am not going to pay exorbitant amount to settle this when it was someone's negligence of not sending me a statement 2 years ago. I need the closing statement so I can pay accordingly.