"No doctor in there at opening times"

We called 111 and they referred us to the walk in centre nearby. The NHS website clearly says they close at 8pm, we arrived at 7pm and the receptionist told us the doctor had already left. We also saw a note on the door saying that if not enough people waiting the doctor might leave early. This is in our opinion unacceptable. We called another walk in centre and asked if they were opened until the time that appears in the website and they were surprised by the question. Given the amount of bad reviews this centre should be warned and made to run properly. The existing situation is unacceptable and NHS should take action.