Is a wife's statement that she did not receive the gold considered a false testimony, knowing that it is in her possession and she wants to obligate her husband to pay its price, and is it permissible for the husband to seek the help of false witnesses to reclaim his right?

What the woman did was bear false witness and unjustly consume wealth, which are major sins. The judge's ruling does not make the gold permissible for her, because a judge's ruling does not legitimize what is unlawful. It is not permissible to seek help from false witnesses to reclaim one's right. However, it is permissible to use equivocation (tawriya) in one's statements before the judge, such as saying "I returned the gold" while meaning "I bought it" or "I sold it," or "I postponed it" meaning "I delayed receiving it." If the woman denies, the judge will administer an oath to her or to the claimant, and it is permissible for the wronged person to take an oath with equivocation.