Bad experience with staff.
We booked our luggage storage at the "New style Council Gamla Stan", and paid for the booking in the app beforehand. When we arrived at the location, the man working in the shop told us that there was no space left for our luggage. We told him that we had already paid, and asked him how we could refund, which he did not know. After discussing with him, he eventually agreed to take us to the storage room. We could clearly see that there was plenty of space for more luggage in this room. It is also worth mentioning that he had the excact same discussion with the people before us in the queue, and when we left he was in the process of telling the same things again to the people behind us in the queue. From this experience we got suspicious that this is used as a method to gain more money for the staff working there.