Never had this problem myself and I've been using CP for three years. It's not a scam imho.
'
I haven't been scammed so it can't be a scam' doesn't refute any of these allegations.
'I've had an issue (quite possibly of my own making) so it must be a scam' - provides no evidence to support this.
You're just assuming it's of their own making. Coinpot isn't making this claim. They're just taking money that people have earned without any explanation. If they're not going to bother defending themselves and remain silent hoping this all goes away then I have to give the benefit of the doubt to the other side which has made an effort to argue their innocence.