Is it considered unlawful for the fiancé to take his furniture without his parents' consent and marry his fiancée despite their refusal, knowing that they object to the completion of the marriage?

Obeying parents in what is good is obligatory, and disobeying them is a major sin. If the parents' refusal to complete the marriage is for an acceptable reason, then the son must obey them. However, if the refusal is for an unacceptable reason, then he is not obliged to obey them, and he may complete the marriage after trying to convince them and interceding through someone who can reconcile between them, while being keen to honor them, be kind to them, and supplicate for them.