Nu Debt - same Old ****

Where do these people come from?

I have retired and am now a pensioner with no TV, and although I paid my license diligently for a number of years, suddenly out of the blue I receive an SMS last week Friday informing me of a trace alert placed on my name for outstanding Tv license, and a request to pay NOW.

Today, Monday, 2 days later (with a weekend in between) I receive another SMS, without any response from me yet, informing me that "I failed to pay as promised on my TV license and to pay R150 NOW to avoid further penalties".

Please, if these are legitimate debt collectors for SABC then some serious action is required here. I have requested twice from SABC advice on how to proceed under my current predicament, and this response from Nu Debt is the reply?