Do you know if your store is currently frozen due to non-payment? Or did you pay that invoice? Were you planning on keeping the store open, or were you going to cancel it?
I have the same problem that i just open store for testing new theme and after that i totally forgot it. I closed this store immediately after received a notification about charging for the monthly plan. So can I get refund? Hope you reply me soon.
I'd be happy to look into that for you. I'll send you an email shortly to authenticate your account and we can have a look. Cheers.