State Bank Of India [SBI] — negligent service

Address: Tumkur, Karnataka

I am indian currently residing in singapore. I used to remit amount from singapore to my father's account. Recently i did two transactions to my fathers account.
My father has account in state bank of mysore tiptur branch, currently merged as state bank of india.
While merger happened, there is a change in ifsc code. Should there be seamless transfer of money in first place or at least the bank should communicate their customers about the new/changed ifsc code in advance? In my fathers case, bank has not full filled their responsibilities / duties to inform the change of ifsc code.
As usual, i remitted the money to my fathers account with sbm in september 2017. Money returned back after about a week to my account saying "wrong ifsc code".in this transaction i have lost nearly int 7500. This is just due to negligent banking services.
Please let me know how to recover this lose and what are opportunities for my father to recover this. Please help.
I trust you will provide some direction to resolve this issue.
Thanks.