******* harassment regarding paid up debt

Despite having received communication from Cell C regards a supposed unpaid debt my husband and I still receive daily calls and SMS threatening legal action. Contact number received from representative at Nudebt gives messages that mail box full and ends calls. This harassment from them is totally unacceptable. I have a letter from Cell C and this makes no difference to Nudebt as they are determined to get money from me regardless of anything I say or do. (This includes deductions from my bank account -small amounts so as to ensure I don't pick it up immediately.