Hi @lambori1990 ,
If you feel that the problem was not caused by your child, and since the watch is still within the warranty period, contact Vtech as per the [https://www.vtechkids.com/warranty_policy/|manufacturer’s warranty statement] about making a claim for a repair or replacement.
If they decide that it was caused by user “misuse” and refuse to replace/repair it under warranty, then here’s a link to the ifixit [[Topic:VTech Kidizoom Smartwatch DX2]] guides, which may be of some help.