The phrase "called in" refers to a person entering a specific location for a certain purpose. When writing, it's important to vary your vocabulary and use synonyms to avoid repeating the same words over and over again. Some synonyms for "called in" include "visited," "dropped by," "stopped in," "showed up," "popped in," and "came over." Using these variants will give your writing a fresh feel, and make your work more enjoyable to read. By incorporating a diverse range of vocabulary, you'll be able to convey your message more effectively and hold your reader's attention for longer.