The correct spelling of the phrase "are on top heap" is actually "are on top of the heap." In IPA phonetic transcription, it would be /ɑr ɑn tɒp əv ðə hip/. The confusion may come from similar-sounding phrases like "a heap of trouble" or "heap of praise." However, in this case, the correct preposition is "of." So, next time you use this phrase, remember the correct spelling and pronunciation!