Subscription Fee Refund - Denied

As some other sellers on this platform I got tricked into subscribing for professional plan when signing up (description of the issue see https://sellercentral.amazon.co.uk/seller-forums/discussions/t/3607b8cd-6e0f-48f0-89ea-abf47a406bd4 and https://sellercentral-europe.amazon.com/seller-forums/discussions/t/4358e9ee-45cb-4d86-9f6b-69ad869b4b8f).

I was charged the subscription fee in July for which I created a ticket and got a refund (case ID: 9938531682). There was no explanation provided for why I was charged in the first place since I opted for the individual plan from the start. I noticed on Aug. 4th that I was charged again for this service on Aug 1st. Now in case ID 10065775002 I am being refused a refund and being send a canned response above about the subscription fee FAQ (link: https://sellercentral.amazon.de/gp/help/GAB9AXEU2FEC4GXM).

I am being told the following: "We understand that you are requesting a subscription fee refund. Your request has been declined because you have used your professional selling tools and benefits."

Needless to say I have no idea which tools and benefits were used between Aug. 1st and Aug. 4th and the support service provided no information on that upon request (so far at least). My last sale was in July. I haven't used the services with that date range (Aug 1st-4th).

I've downgraded explicitly the account to individual plan (following the instructions from the FAQ). In principle I'm willing to accept the situation with the extra charge as long as it is explained what exactly did I use in the mentioned timeframe. So far seems I'm getting a canned response from the support (is it even from a human operator?) without any clear explanation of my case.

Regarding the FAQ there is this question:

"""

I did not use any tools and want to end my Professional Selling Plan. Will I get a refund?

You are eligible for a Professional Selling Plan refund if you have not used any Professional tools or benefits after signing up. If you want to end your Professional Selling Plan, you are eligible for a one-time refund of up to 3 months, and your refund request needs to be initiated within 90 days from the payment date of the Professional Plan selling fees. If you meet these criteria, use the tool below to request a refund.

"""

As I didn't use the services in August looks like I'm charged for the usage in July for which I got a refund with the first ticket (9938531682).

I'd appreciate an explanation of my situation from a knowledgeable human operator in this case.