She phoned them and they basically said "hard luck, that's where the market was by the time we filled you".
Seems to be a breach of T&Cs....
Term 11(5)...
When we execute an Order, we will do so within a reasonable time of the Order being triggered and, subject to Term 11(10), we will seek to execute your Order based on the first attainable price that might have been achieved had a similar order (including as to size) been placed on the Underlying Market. Notwithstanding the foregoing, you acknowledge and agree that (a) the first attainable price may differ from your specified Order level; and (b) that it may not be possible to determine what the first attainable price might have been. Accordingly, we do not guarantee that your Order will be executed at your specified level and you acknowledge that the time and level at which Orders are executed will be determined by us, acting reasonably.
I'll get her to ring again.
Steve.