I once told one of them I use a Mac then they hung up and didn't call for a while then after the lull they returned with different people but the same schtick only then I said I was running Linux which ended the calls for a while again... On the third time I said I have a keyboard plugged into a potato and told them to bugger off, the guy then got hysterical and I think was swearing in tamil or something. That was a fun day.