If you compare min/max chart (to be precised set 5-sec chart and to make zoom) to spread on the Quote list, you will see different spreads. For example on eur/usd oanda shows 0.9 but different between min and max is sometimes 6 pips! Generally when market makes sharp move Quote list shows 0.9, min/max - 6 pips!
I've checked other forex brokers, nearly all do this. Some would say it's not a scam because many of them do it in fast moving markets. Personally I think it IS a scam because the frequency it's done really rips into profit margins to a point where you won't be able to make much money and will be fighting just to break even.
Please can you post some screenshots to support what you say. Here are the spreads from the broker I use, they seem fairly competitive to me...