Samsung — Galaxy a3 service issue

Address:

New Delhi, Delhi, 110032

The HOME KEY of my phone galaxy A3 was nor working and I took the issue to the service center, the technical person who was attending me check my phone and he was convinced that the key was not working and he replaced the part.
After replacement of part they are saying that your phone is damaged
But when I bring my phone at service center my phone was working absolutely fine even the technical person has ensured the same .

Please look at the issue seriously ASAP.

Regards
Dushyant verma
Ph no [protected]