Legal analysis: After signing a slimming service contract with others, if one party goes back on his word, he can ask the other party to repay the contract money already paid, but he also needs to pay the other party liquidated damages according to the contract.

Legal basis: Civil Code of People's Republic of China (PRC).

Article 577 Where a party fails to perform its contractual obligations or fails to perform its contractual obligations in conformity with the contract, it shall be liable for breach of contract such as continuing to perform, taking remedial measures or compensating for losses.

Article 578 Where a party expressly expresses or shows by his own behavior that he will not perform his contractual obligations, the other party may require him to bear the liability for breach of contract before the time limit for performance expires.

Article 566 If the contract has not been performed after dissolution, the performance shall be terminated; If it has been performed, according to the performance and the nature of the contract, the parties may request restitution or take other remedial measures, and have the right to claim compensation for losses. Where the contract is terminated due to breach of contract, the creditor may require the breaching party to bear the liability for breach of contract, unless otherwise agreed by the parties.