Broken down Gigabyte GB-P750GM PSU - advise on RMA process

Hi,

I had this gigabyte 750w modular GPU in my daily driver. One day my PC didnt start with power cycling every few seconds. thought the PSU might have broken. replaced it with another 650w unit I had and it worked.

checked warranty on gigabyte website and the PSU is in warranty till Aug 26. I think I had bought it from SMC International, Nehru Place about 2-3 years back but dont have the bill now. I found the gigabyte service center address in Nehru place but before going there, trying to get answer to 2 questions from more experienced folks here:

  1. Do I need the bill or the s/n is enough? I dont see a reason why I’d need a bill and if people do keep paper bills forever, but checking in case they try to make RMA process harder. if they do, what are my options?
  2. do I need to raise a online ticket before going to service center or can I just walk in? couldn’t find a place to raise a ticket online so checking.

Thanks if anyone can advise.