I want to get my subscribe refunded

Hello, I did request refund in apple support. I am using Marginote 4 on my Mac in pro mode. However, all of a sudden, Marginote opened in free mode only, and I was unable to restore my purchase. Since my exam is coming up soon, I need to use the pro mode. I discovered that there is a 7-day trial mode available, even though I have already used the trial mode before. It says it is definitely free until June 15th, but once I click the button to subscribe, it starts subscribing without the trial mode

I am not sure how to switch Marginote 4 from the free version to the pro version again, like I did before. My previous attempts to do so were unsuccessful. I had already purchased Marginote 3 in order to upgrade to Marginote 4 pro.