What is the ruling on someone who swore "100 oaths and 100 mighty oaths" not to carry a phone, and then carried it?

The saying "by my right" or "by 100 rights" is not an explicit oath by Allah unless that is intended, or the name of Allah or one of His attributes is mentioned. If a person intends by it an oath by Allah, then it is considered an oath. If a person swears multiple oaths to do one thing, and then breaks them, only one expiation for an oath is required of him.