Your not being attacked personally. They are just bots stationed out of china, or rerouted through there. Its like telemarketeers. They are calling you, but there not really calling "YOU"
Also, unless you have a buisness account, I would be very surprised if your ISP did anything. Its not enough to be considered a DoS attack, and its legitimate traffic, just with illegitimate intent. Good point about blocking them though,. If there intent is to gain entry into your network, or atleast probe it, best to block them. Then again, the act of blocking a port sets it as closed, which may alert them more then a listening port.