Ignoring my emails

Ref nr BOT0020005647. I have an account with these people. I have been handed over to them. My daughter has a trust and for the trust to pay this account the trust need an invoice with my daughter's name and surname on. I have send numerous emails through to a Melissa van Zyl last week so that I can send it through to the trust so that they can make a payment. I am struggling to get that invoice from them, they keep on ignoring my emails. I keep on receiving threatening messages that the Sheriff of the court will come and take my stuff. So what must I do if they do not want to give me that invoice? It seems that they do not want the money but now they are threatening me. I'm doing my part to have this money paid but they keep on ignoring me.