In case of return,do we have the option of store credit as well apart from refund into the customer's account?

You can provide loyalty/wallet points to the user in such case. You can install the app from your StoreHippo aadmin panel from App section under Advance settings. Find a brief about the loyalty app below:

1 loyalty point = 1 rupee

You can use the loyalty points for multiple purpose:

a) If a user asks for refund you can transfer wallet points into his account from Customer> Users
b) You can give loyalty points to the user at the time of registration and mention max and min points that they can redeem.
c) You can mention specific loyalty points for specific products as well.