Samsung — Rearding Mobile issue

Address:

Samsung India Electronics Ltd. 7th & 8th Floor, IFCI Tower 61, Nehru Place, New Delhi-110019 Telephone: (91-11) 4151-1234 Fax: (91-11) 4160-8818/19

As i had purchased the Samsung A31 mobile on dated[protected] from Santos communication soap Patna after three months my mobile phone was automatically banded. For repairing my mobile I was visited Samsung service center Digha asiana road Patna on dated[protected] but service center is diny to accept my mobile for repairing purpose.
As my phone is in warranty period So, I had call the customer care and requesting then to please resolved the issue my phone after several conversation through phone and email lastly the ready to repair my phone.
So, On[protected] again i had visited Samsung servise center Digha asiana road Patna, This time they had taken my phone for repairing purpose but on next day they had return my phone with more issue.
When I asked him about my phone issue the samply said you have to pay for your phone service. As my phone is a warranty period so why shuld I pay for this.
Kindly look into the matter.