After the victim broke up, his ex-girlfriend swiped his credit card without authorization. If the total amount reaches 30 thousand yuan, it constitutes a "large amount" situation, which has been suspected of constituting theft, and the victim can call the police. Article 264 of the Criminal Law stipulates that whoever steals public or private property in a relatively large amount, or repeatedly steals, enters a house, carries a weapon or pickpockets, shall be sentenced to fixed-term imprisonment of not more than three years, criminal detention or public surveillance, and shall also, or shall only, be fined.