My first thought was "Dear 'AD', we have just received this rude and hastily-typed email purporting to be from you; is it real??" -- so maybe it wasn't really from AD at all. Maybe all these emails are being spoofed by sock-puppets (no relation, I know! ;-)

Telecoms are usually very helpful too (& TBH I don't think their email was unhelpful/inaccurate/impolite -- just v bad spelling).