Can I withrdaw some satoshis form memo to yours.org?
No, not directly. But by exporting your key, importing it to some BCH wallet, then sending some satoshis to your yours.org deposit address.
I tried it, BCH wallet shows me that my balance is 0
Strange. I just did it, exported the key, created a new Electron Cash wallet from that key (compressed), and the balance and all the tx are there.
Just as I 'Post Reply' here, I can see a new tx in the wallet.
You are right, I did something wrong then. Now tried with compressed pk and it works