I was able to amend my 2018 tax return and was not charged however I could not efile.  I had to mail the IRS a hard copy.

Yes you will get charged if you have to upgrade to a higher version when you amend.  Or you add a state return or some other service.

  How to review your fees https://ttlc.intuit.com/replies/4202093 

I'm being charged $40

If the information you need to Amend in TurboTax requires an upgrade to the next level of TurboTax, you will be prompted to upgrade which will result in an additional cost. You can review your fees to see a breakdown of what you are being charged for. 

Well this is a lie cause the made me purchase plus and now that i figured out that i didnt need it i cant seem to get my money refunded

Please click the link below to contact Customer Support for assistance.

What is the TurboTax phone number? - Community

They are telling me I have to up grade to amend

Please see the Customer Support phone number below for further assistance:

https://ttlc.intuit.com/community/using-turbotax/help/what-is-the-turbotax-phone-number/00/25632

If you would like to reach out through our website, please see the TurboTax FAQ below for contact information: https://support.turbotax.intuit.com/contact/