If it's making you worry, honestly don't- that's such a rare occurrance. It is much more common (there were articles about it a while ago) for people to apply to top, competitive RG unis, mess up their exams, and get in with 3 Es, than for people to get rejected with 4 A*s. The only British unis that would realistically reject you with those grades would be Oxbridge and possibly Durham, but even that would be pushing it.