I subscribed to Shopify’s 3 month trial but I forgot to change the plan and was charged $399

[ae4]

Hey, I just started using Shopify and I subscribed to the 3 month trial and when it was over Shopify charged me $399. I meant to continue on with the basic standard Shopify plan as I cannot afford the advanced plan. I’m just a college student and I really need a refund on this.