Hello,
Thank you for getting in touch. Not all is lost. If you remember your SIM card number, you can attempt to turn mobile WAN on via SMS message. Simply send the following SMS messages to your router’s number:
<Your router's password> uci set network.mob1s1a1.disabled=0
<Your router's password> uci commit
<Your router's password> reboot
This reboot should reestablish your mobile connection, and the mobile WAN interface should become accessible again.
Best regards,
Marijus