Help With My Japanese, Please Help!?

Okay, for my first question, I was wondering how you say "Why won't you call me?". I think it would go "Anata wa doshite denwa o shimasen?", but I was thinking that it wouldn't be a question without the ka at the end, but doesn't a negative question make it more of an invitation? So how would I say it?

For my second question, I can speak (basic) Japanese fine, with a delay, of course, as I'm new, but I have trouble understanding others. I take so long to pick out the words and say what means what, so I can understand what they say. How can I speed up my hearing fluency? Just keep hearing it (I'm doing it in songs, a little anime, etc.).

Finally, I have to ask, how would I say something, while giving it a description? Like "I want delicious ice cream", or "I read an interesting book". I don't want to say "aisukarimu wa oishi desu kara aisukarimu o tabetaidesu". I don't think that's how you spell ice cream, but whatever. I want to say "Watashi wa omoshiroi manga o yomimashita". Is that acceptable? What would be the equal to what I'm trying to say? Thank you. You don't have to answer them all. Thanks twice more. Or even more appropriate, arigato gozaimasu.