GO FUCK YOURSELF!!!
Contrary to corporate propaganda perpetuated, primarily against women working for US companies foreign call centers - the customer IS NOT always right. In fact, the customer is just as often not only wrong, but rude, belligerent and offensive, but can be requesting that we do something that is not possible or simply illegal.
Other customers are willfully ignorant, having refused to listen or to bother to read the information on the website or in the emails that they were politely and repeatedly requested to read. So they continue to repeatedly call from the cheapest VOIP service, that hangs up as soon as it is answered, and if it does answer the static on the line will be too much to hear what they are saying or, perhaps it is the party at the bar (they will claim it to be an internet cafe) that they are calling from.
It is really best to not tolerate this behavior from customers, as they will simply be unable to complete their transaction if they do not take instruction seriously, and they will be the type that will be the most likely to complain about charges after the goods have shipped, or abandon their goods completely.
Our experience is that after being told to "GFY" by one person at A2 Global Shipping, many customers will simply open up a new account at A2 Global, under a different name and direct all of their communications to another department or specific person at A2 Global who is better able to tolerate their idiot-cyncracies.
I have known perfectly polite and competent women, working in customer service who have been put to tears, or in need of blood pressure medication by a series of repeated calls from a bad customer. Our calculus is that more damage is done by a bad customer contacting us and wasting our time, than by telling that customer to "GFY" and having them complain to everyone they know. Everyone they know, probably knows how they are and will probably want to know what nice company tolerated them at all. Even better is if the former customer goes and posts stories all over the web. Even if the stories are all lies, they will do more to increase our Google search position and web traffic than to discourage potential customers.. Ironic, is it not?