IMHO it is a bit harsh. Keep things businesslike and neutral, you don't want to show emotion when these things wind you up.
As for her whingeing about postage costs, she shouldn't have bid if she didn't like the cost!
I would ignore that and say something along the lines of
"Thank you for your e-mail. I will of course contact the manager to get a letter for you but please be advised this may take some time and your patience is appreciated.
Regards"
As for her whingeing about postage costs, she shouldn't have bid if she didn't like the cost!
I would ignore that and say something along the lines of
"Thank you for your e-mail. I will of course contact the manager to get a letter for you but please be advised this may take some time and your patience is appreciated.
Regards"