Dealing with death

I'm quite disgusted by the Woolworths call centre agents. I emailed Woolies informing them of the death of my husband, the account holder. I received condolences so that was fine. Since then I've been called constantly asking to speak to my husband. When I tell them he died last month, I'm his wife, how can I help? They bang the phone down and it goes on and on. One was a little different and harshly asked me to produce the death certificate at a store. This I'm not prepared to do but will gladly email it.