They sell a weekly pass which grants you access to a special shop from where you can buy things for coupons. Once bought, the weekly pass is active for 7 days and you can use that shop for 7 days. I bought it 6 days ago, and haven't been able to use it for 5 days. I reported it to their mod from the official discord server and also emailed. No reply still from anyone. The game forced me to buy the monthly subscription in order to use the weekly shop. But I still can't use the shop for which I pa