Amazon - Self return not possible

I ordered a set of * track pants. Ist issue is that they are smaller in size and secondly one of them is quite different than what is shown in picture. Now that I want to return them, they are asking me to self return. The package reached to me by india post. It's not possible for me to self return since the courier office is at a distancs of about ** to ** kms away from home and that too in lockdown from kashmir. Who is going to pay me the money? Since the costomer service are not taking responsibility. This is my loss only.. Why ony one side loss? Why did not they inform me before that They will send me via post and return would be self based if needed. Why only one side loss?