Hero Electric — Hero NYX motor complaint

This is Elumalai([protected]) from Chennai, Tamilnadu Nadu. 7 month before I purchased HERO NYX(TN13V2815) from thanya motors Chennai. 5 days before I went showroom for my second service. Showroom technician said it is motor complaint, you need to replace, and showroom manager said it's not covered under warranty.. I'll send mail to Hero company, I will change the motor if company gives approval. Otherwise you need to pay.
Now what can I do ... I'm a milk delivery man ... scooter is necessary... that's why I purchased your product..and I trusted your company.. not even one year completed I'm facing this issue...till now my bike is not delivered back to me.. kindly help me