When it's very clear to me that someone doesn't value my communication with them, I wouldn't bother having any kind of engagement with the person again even if they try to talk to me again.
Once I'm online, I reply almost instantly usually within seconds because I don't like keeping someone waiting for my response hanging too long.
It's only someone who is a douchebag that is going to read a message and ignore to reply after reading the message.
When it's very clear to me that someone doesn't value my communication with them, I wouldn't bother having any kind of engagement with the person again even if they try to talk to me again.
Someone did something like this to me. I will try to engage conversation between us but the way she does made me understand that she don't value my communication with me. These days she's trying to talk to me but I don't even give her the face she wanted. Sometimes, I will leave her unread for some weeks before responding.