My amended tax return was completed last Thursday when will my refund show up

Do not expect quick results from amending. It can take four months or more for the IRS to process an amended return.  

You can watch for information here:

https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1

A federal amended tax return can take up to 16 weeks or longer for the IRS to process.

Go to this IRS website for the status of a federal amended tax return, Form 1040-X - https://www.irs.gov/filing/wheres-my-amended-return