Repeatedly means again and again, many times over. Once would have been enough, and it was not once.
The word almost always carries impatience or emphasis, which is why complaints and legal statements use it so heavily: repeatedly asked, repeatedly warned, repeatedly failed to respond. It is stronger than often, because often spreads the events out and repeatedly stacks them up. It usually sits between the subject and the verb, or right after the verb. The adjective is repeated, and the noun is repetition.
1adverbrepeatedlyMany times over; again and again.
“He had repeatedly been told not to park there.”
From repeated + -ly.
Etymology from Wiktionary, CC BY-SA