Audiologist recommendation in India (Chennai if possible)

My dad has severe sensorineural hearing loss and when he visited me a few years ago here in the US, I had gotten a Phonak Brio 3 for him from Costco which worked very well for him. Now, these are not working as well for him, so I’m looking for recommendation in India (Chennai would be preferable) for audiologist/dispensers that he can go to. The ones he has been to have generally been unsatisfactory, do not offer demos/trails on new aids and are unable to tune his current Costco Phonak Brio 3 correctly.

Thanks in advance!

Phonak has locations in Mumbai,Bangalore and Delhi(Regional office) but not Chennai but you can contact them and find out authorized Audiologists in and around Chennai.