For personal protection I am not giving my name, but I am a long-forgotten VHP author who has faced the same problems you have. Everything was peachy-keen until my book came out, and then suddenly I was forgotten. After nine months of badgering, I got one royalty check, and then I guess I just ceased to exist in their eyes. All my prompts for payment and notices for new manuscripts were ignored. Eventually my book fell to the bottom of the heap, and now it's gone. No letter, no note, not even a one-line notice of my book being discontinued. Nothing. I literally discovered this when I went to the site to link a cover of my novel to my new web site. I felt ignored and neglected--treated very rudely, at the VERY least.
As far as book publishing goes, I am not sure where I will go from here--I'm more into writing short stories for literary journals now.