Why my Lumia 730 speakers are not working?

[Windows Central Question]

Many times it was in rain but this time it lost it sound systems. In the software also, when i press volume button, nothing comes down. Please can't hear my voice. I can't even play any videos, music or youtube on my phone. I have taken it to Nokia Care, but they gave-up like if they touch speakers on mother board, total phone will be dead. Please can anyone help with this. Can i have spares available or repair the speakers without issues.