@Ash84 It is not your bill, only a 'helpful' picture of your data that has gone wrong. You can ignore it and wait for SP to sort out their technology, one day.
I had this as well. Suddenly on a day in a June I apparently spent nearly £600 on energy. Ridiculous. Got onto their chat to get this ridiculous estimate taken off and their point was it would all get sorted with the next reading and bill. My point was I'd had a reading (smart meter) 7 days previously. After much forward and back I finally persuaded them to take a reading there and then to recalculate and hopefully remove the ridiculous estimate. Checked in this morning, new bill at around £60 but, wait for it, that ridiculous estimate for the one day in June now over £2000! They are so amateur and are either deliberate inflating estimates or just incompetent.
@ghill You can ignore the £1000 usage for June 2020, the usage charts are not your bill. Anyway if it was important 9 months ago you would know all about it by now.
The usage charts often go wrong and if they are showing impossible figures just ignore them