Honda Activa — thumb starting gone

Address:

Tiruvallur, Tamil Nadu

it is only 9 years back we purchased our HH. Now it is impossible to start by thumb switch. Service Centre at Tirumullavoil said us to replace the engine ...which will cost around 15000. it seems it is not a service center but a replacement center. local mechanic said babbit m/t can be deposited and ground to come to Factory condition which will cost 1000+. another mechanic told the cyllinder can be replaced at 5000.