Taz,
I've been lucky and not had many issues in my time trading.
In terms of broker error on the trade side, the steps I would suggest are:
1) Informal inquiry to the broker (expect fluff)
2) Formal complaint to the broker's compliance department
3) Formal complaint to the proper authorities (depends on what instrument being traded. For example, the
NFA governs futures. The
SEC for stocks/options. The
NFA can help as well in some forex cases.)
Keep records of all correspondence and only communicate in written fashion. Tell the broker to put all answers in writing.
From there it's a matter of how far you want to push it. In a serious matter, contacting a securities lawyer is next.
And as for data errors, I would simply suggest getting a new data provider. There are so many outs for the vendor with the agreement that you agree to that it's really much easier to get new data. And if need be, a new broker in the process. I was having a major issue with DTN data at one point that after spending MONTHS going round and round with them it was just easier to find something new. The one thing I learned about data issues is that every party can point to another party as the one at fault that you will never really know what the issue is - broker points to data feed company who points to the exchange who points to YOUR ISP who says their stuff is fine so it must be someone else's fault.... You'll end up doing this -
