@eSPiYa Hey I'm not staff or anything but I may be able to answer a couple of your questions.
The first one depends on how you subscribed. Currently there is a "regular" and a "premium" subscription. If you subscribed for the premium member, then you receive a premium credit once a month, every 15th of the month. This credit can then be used to purchase the E-Book through this website, otherwise you are welcome to purchase the E-books through other distributors that J-Novel Club has connections to. I don't know them all off hand, but Amazon is one of them. If you would like to purchase additional premium credits, I believe the option is available now to purchase one for $6 through your account page.
In regards to your 2nd question, once you purchase the E-Book it should be available to download from your account library (assuming you buy it from here). After that, connecting it to whatever E-Book reader you're using should allow you to read it offline (I imagine). I'm not too knowledgeable in this area so you may want to confirm with someone with more experience.
Lastly, anything you purchased from this website is available for download so you can reread whenever you like. As for if you forget to download it and your subscription ends, I don't believe that makes a difference as it should already be purchased and linked to your account.
@erictbar Yeah, fixed that too!
It removed you from the Premium Members group but failed to add you to the Members group for some reason, that was the error you saw. It doesn't attempt to do this until after the subscription goes through obviously, so I should make sure to figure out what is going wrong with the Member group adding and in addition add a sanity check before creating a new subscription that you don't already have an active one.
I actually built the system to be able to handle multiple subscriptions on the same account simultaneously... (like for example if, in the future, we have separate subscriptions for josei novels or R-18 novels... something like that?), but it's not really practically useful right now.
First off thank you for taking the time to reply to me, I know you have a lot of work to do so you even replying to my topic makes me happy.
Second I think I found a work around to this problem, this glitch seems to occur if I leave my tablet on for long periods of time, however if I reset it that seems to fix the problem. Sorry about all my complaining when the actual solution was so simple.
@ImIlyaz Yup! If you're never going to use the reader or apps and just want the epubs, then go buy them. You'll be able to purchase premium credits to buy epubs directly from us soon, too (although you won't get as good a price as Premium Members would).