Ok, so I read it and it looks like I got screwed. I’ll leave the important information here for others so you don’t get into the same situation as I am.
Gift vouchers are valid for one year and credits are valid also only for one year upon redemption. In other words, if you wait to redeem the vouchers, your credits can be valid for up to nearly 2 years. This was not stated in the voucher, however, so I redeemed them right away without much thought, so now I’m in the situation where I could potentially lose credits because of changes in life. It also means I now have less than one year to use my credits as I still have my subscription credits left.
Once again - do NOT redeem your voucher unless a) it is expiring or b) you need more credits for taking lessons.