Continuous phone calls from accounts department

Was recently hospitalized with the birth of my son. There is a small outstanding amount which was not covered in-hospital by the medical aid. Only received my statement on the 15th of December, since the 21st of December, Lancet has been calling me daily. My account is not even 30 days outstanding! From my account history it can be seen that my account is always paid for and settled. I feel it is completely unnecessary for Lancet to continue calling me if they don't even give me time to settle the account by month-end.