Das bezahle ich nicht!
Why does Duolingo use this construction instead of "ich bezahle das nicht"? Does the sentence above like express more anger or frustration..??
Putting 'das' first puts more emphasis on it. It's a perfectly normal construction that you should be comfortable with.
English uses word order to show what role words play in the sentence. German relies more on things like case for that and so has a much more flexible word order than English.