They replied to me right away about all my questions and sent me details about their location. so it was easy to find their place. It's located 10 min away from the old city area and 8 min away from the bus station. They let me check in earlier as I arrived in San Sebastian in the morning.
Their place is very clean, fancy and comfy. I wish I could stay longer... I will definitely stay again when I go back to San Sebastian. Thank you for the warm hospitality!