Harassment from Standard Bank Retail lending department

I spoke to the retail lending department on Monday and after I explained to the call centre agent that I will only be able to make a payment at the end of the month, she decided not to make notes on the system because I can not make a payment now. Since then I have received 5 more calls explaining to the call centre agents that I have already spoken to someone. Now I have received 31 sms messages from Standard Bank which are voicemails in 24 hours. This is harassment, I have asked to speak to a supervisor but then they just put the phone down. I even tried to send them an online complaint but in 48 hours I have received no response