Disgustion Service by OnAir Tv

On Air installed a Dstv Decoder for me with monthly payment agreement of R160. The business has my banking details to debit my account every month. Since the beginning of this month i was subjected to SMSs from OnAir to pay R320. Today I received one such SMS as FINAL NOTICE Failure to pay will result possible action on my account. The number (***8) the have there as contact does not get through when one call, untill today when i got this SMS, I decided to google this business and instead found a diffent number (Phone: ***). I called and talked to lady who explained that there was a problem between Onair and Banks and that made the debit orders not to go through. The problem here is that OnAir has been sending threatening SMSs withouth have tried to explain the problem to customers first. The never bothered to call nor send SMSs to explain what the proble was, but have the audacity to threaten customers. This is very unprofessional. At least if the sent messages or called to explain this problem, it would be understandable. This is disgusting service. Please help, because when i asked to talk to someone senior, they made me hold onto the phone for so long I eneded up hanging up.