No worries. TBH they are an absolute shambles, not very professional at all. On several instances I have agreed a time, travelled to the nearest tube and called them again only to be ignored (phone either off or not answered). They always text the same shit excuses like "landlord is here, im so sorry we have to push it back 30 minutes"). I even remember one time I was about to walk up to the flat when I saw another guy heading the same way whilst on the phone, and I overheard him saying "ok so you are flat xx?". When I called up about 10 secs later, the woman on the phone said "I thought I just let you in? OMG I'm so sorry I made a mistake and let someone else in to see the same girl", even though I had called about 2 hours ago for that exact time, so they clearly just work on a first come, first serve basis. I am not exaggerating when I say that I have frequently punted with them with sometimes just 1 minutes notice when I am in the area.
But I put up with them because the quality of the girls and service is excellent on the whole. I just make sure I always have a plan B. Luckily, because their flats are well located in the heart of the city, it's easy to go elsewhere if your punt falls through. If I was travelling from far though, I would stay WELL CLEAR of this cowboy operation!