Consultant won't continue because of incorrect postal code.

Consultant will not continue on call because postal code is incorrect. Firstly I would like to start of by saying that I understand that it is compulsory for an agent to do a security check however how does an incorrect postal code determine if you are chatting to the correct or incorrect person .Could she not ask another security question?instead of telling you that she cannot help because you don't know the correct postal code. Other companies ask more questions. I seriously think your service is very bad and you need to train your employees. What is it was an honest mistake.