I’m afraid I must concur, the cost to replace/repair the damage to the existing yoyo would probably be to much and more cost effective to just purchase brand new better quality yoyo.
As Logi noted they do not automatically come back, or return. Wile he is correct, that is not entirely true. The yoyojam Classic is what we call responsive meaning that unlike the Yomega Brain which has a auto return mechanism, the yoyo will sleep at the end of the string for a short wile however, with minimal effort and by tugging at the string the yoyo does return quite easily.
What is also nice about these yoyos is that they can be modified by purchasing cheap side products (i.e. unresponsive Bering, smoother response pads ect.) to accommodate greater skill levels later in life.
I to ran an after school program At my school. The club was devoted just to yo-yoing (yoyo club, a fitting tittle) we bought three classics for the students to use, and as they grew in ability and interest persuaded them to start purchasing there own better higher quality yoyos.
I hope this helps,
If you were to specify on the problem with the Brain I may be able to help you further.