Cancelling service due to dismal customer service, questions about credit

I've been attempting to get IPv6 support enabled for months. No one responds to my messages or forum posts any longer, and posts on here conflict with what I was told from L2 business support (bridge mode doesn't require a static IP on here, vs bridge mode requires one from L2 support), plus I've been BEGGING to get my modem fixed. 

When I cancel my service, can you give me a partial credit or do you keep it?