Problematic shipping cost calculation

Hello,
As i have seen, the chrome extension is taking a 3$ shipping cost in products which have choice delivery, but are above 20$ so free shipping (in context of my country Qatar).
Please fix this, I don’t want the shipping cost to be 3$ for the choice products having free delivery.

Or at least, please give me an immediate beta plugin that puts shipping cost as 0 for all products with choice delivery

Thank you