Refund for UNAUTHORIZED Shopify subscription fee

[Yknb1]

Hi, I had charges that were UNAUTHORIZED after my $1/mo x 3 months trial period for 1 year that I did not know until I was reconciling my cc bills end of year/tax season. In my shopify account, I even CANCELLED the plan so I won’t get charged after these trial period was over. 

I have contacted the billing department to get my money back because I did cancel the plan and was still WRONGFULLY charged, WITHOUT my consent. 

However, all they are refunding is partial of these unauthorized charges. 

I am a mother of 2, pursuing my online entrepreneurship, and Shopify, you cannot take peoples money and not give back especially when a user UNSUBSCRIBED from your service. These charges were done even after I cancelled the plan and unsubscribed from the terms and conditions. 

I have all the documents to show that these were charges that I did not authorize.

Anyone had any similar issues?