1, don't wait too long, because the longer you wait, the more difficult it is to obtain evidence.

2, professional lawyers can grasp the key points, understand the law, know yourself and know yourself.

3. Keep the original contract, and negotiate to use the copy.

4. Get strong evidence from witnesses, partners and other relevant personnel as soon as possible (preferably in written form, signature and fingerprints).

Finally, I wish you success.