What these accusations usually involve
Common versions include contact that continued after someone blocked a number or asked for it to stop, and a dispute that migrated from one platform to another. Others involve messages sent in the worst hours of a breakup or a business falling out, or posts written about a person rather than to them. A friend or relative who sends something on your behalf can bring it back to you as well. The line that gets quoted in a complaint often reads very differently with the exchange above it in view. That is why the complete thread matters more than any single message.
Preserve it, do not clean it up
Export the whole conversation rather than screenshots of selected parts, since dates, sender details, and order are what make a record usable. Keep call logs, account handles, and anything showing contact in the other direction. Deleting messages, wiping a phone, or closing an account after hearing about a complaint tends to become a separate problem, and it is usually visible to the other side anyway. Stop sending anything further, including an apology, and let contact go through counsel from here on.
What we establish early
We work out precisely what is alleged, because these complaints are often broad in summary and thin in detail. We check whether an order limiting contact is in place and what it requires of you now. We also check whether the account or device attributed to you is actually yours alone, since shared phones, shared accounts, and household logins come up more often than people expect. Then we go through the realistic resolutions, and what a record of this kind would mean for your work.