Reading the replies you're getting here makes me understand why there's so many rude people contacting customer service...

I have a customer facing job and I work closely with the customer service department so I'm exposed to a lot of this (I meet customers face to face as well), and it's shocking how rude and abusive some people can get to another human being.

I tell people all the time to stuff their attitude up their holes and start over if they want any help from me. I'm a human being; I will not accept people talking like that to me.

Those customers sure wouldn't accept it if I acted like that to them, why should the reverse be okay?

I think it's a combination of never having contact with customer support or public-facing jobs and this american thing of expecting employees to be on top of customers. It's also a culture thing. Since you are Greek I guess you have a similar understanding to mine on how customer support should work.

I think you were quite reserved. If you were responsible for fixing something in a company and a colleague spoke to you like that, you'd have them in arbitration faster than they could apologise.