@Stuart *******
right you applied for a one year extension you got a 30 day under consideration stamp that told you to go back on the 20th of June, which you did and then you got a yearly extension of stay (again which is NOT a visa) inked into your passport that is valid until the 11 June 2020.
read the first line on that stamp it says "extension of stay permitted up to" <- that is why I said you're on an extension of stay ;)