2 weeks ago I had a small parcel sent to Berlin, the online quote was over £10 but when my mum went to post it we were only charged £2?

Now I don't really get on very well with the woman at our village post office I feel she has screwed me over somehow.

I have sent several items next day with them before from that post office and they have taken a few days to arrive, now I'm either unlucky as everyone I know never has this problem.

All I do know is that my mum did screw up as I guess it was un insured if it only cost £2, I do have a reciept but I have no idea if that is any help.

Can anyone advise what to do as I'm just about to lose out on £120 of parts.

Thanks in advance