"I have had the worst experience with…"

I have had the worst experience with HFM.
The slippage on the zero spread account was too much even on days there are no news. I even took a step further to contact customer support but those guys told me it can happen. But surely for all trades there is slippage? To make matters worse , l trade using market orders and last week on Thursday HFM decided there prices were not getting to my limits when i clearly see on other brokers went down with over 5 pips(XAUUSD).
I dont recommend HFM , Its the worst broker with the most rude customer support