My Iphone 13 pro having white screen issue and problem with speaker. I live in Bangladesh and authorised service provider here denied to provide warranty service. What to do now?

My Iphone 13 pro having white screen issue and problem with speaker. I live in Bangladesh and authorized service provider here denied to provide warranty service. I bought this device from Russia (Mvideo shop) during my visit there. I still have 20 days warranty left. Please help me how to claim warranty from Bangladesh or at least how to connect with customer support.