Dial a rod came to the rescue.

I live in a tenement building in Edinburgh, my drains were blocked, I called a plumber he could not clear the drain, so recommended dial a rod, they came within the hour, a real emergency service, cleared the drain, and also fixed a leak, it turns out they are all qualified plumbers, and been clearing drains for 25 years. Highly recommended. And the best bit was they were very reasonable . Tom Davies