I was in the queue to buy metro tickets today and a couple of tourists were having a hard time purchasing them. I wanted to explain to them that the old one pound coins were removed from circulation yesterday. I told them 'they have been removed' instead of 'they were removed'. I think I made a mistake because it is an event that is finished in the past but somehow it emphasizes something in the present. For me, there is a grey area between those tenses and I would deeply appreciate help.
The only issue I still had with PP was described in the british council website. 'for something that happened in the past but is important at the time of speaking:' and then the example was 'I can’t get in the house. I’ve lost my keys.'. But I realize that this can be put in the same category as something that happened in the past and we don't care when.