Can help me understand this from Tickmill?

Did I misinterpreted it wrongly?

This is my strategy.

This is their reply.

So did I read it wrongly?

Sorry. Comprehension isn't my forte.

Apparently you complained about slippage on a Canadian Dollar trade. They say you straddle limit orders before data release, and due to the added volatility at these times, you need to understand the risks and realities of slippage.
In other words - these things happen, better luck next time

stoploss to tight

you can't blame the broker for this, this was one of the strongest moves you see in fx. economic news came out and was 5x than expected in employment numbers... i mean what did you expect will happen OP.

dept of book was empty.

your 50k contract had no takers at the stop level u placed so it was closed at next best level (at that time) /

eg, i need to close my 50k contract

price / volume avail

1.1 / 10k
1.2 / 20k
1.3 / 30k

my 50k contract will be closed at 1.3, not 1.1 even thou i set my stop loss at 1.1 .

because 10k is not sufficient to close my 50k contract in full. but 1.3 is. (10k+20k+30k) tis is called negative slippage.

there is also positive slippage(in client's favor)

bearing in mind that vol availability changes in split seconds due to other people taking the volume or lps withdrawing due to major news. in this case. i suspect it was major news.

not singling you out.
but in general for most retail traders. before pointing the gun at brokers. understand the market and structure. its usually these type of nuisance complains that get escalated up to regulators and that is why they are all clamping down on leverage.

basically slippage happens, and the slippage related to open/close of this trade is not related.