Most doctors would probably like to see products such as Savlon banned from sale. (Anyone who has ever done a first aid course will tell you that antiseptic creams can do more harm than good, because they inhibit the body's repair processes, and should never be used except under medical direction).
4 days of antibiotics isn't long. When my foot suddenly started swelling up, a few years ago, the doctor prescribed a fortnight's course of antibiotics. I went back a fortnight later because there was still some heat and swelling present. He wasn't at all surprised because he said that feet infections often take quite a long time to clear up, so he gave me a further fortnight's course of antibiotics. The doctor still wasn't surprised when I appeared in his surgery two weeks later with a lingering 'hot and tingling' feeling in my foot. It was only the third two-week course of antibiotics that eventually dealt with the problem.
While I've been typing this, I've seen that Sqad has just posted, suggesting getting the infection checked out again by your GP. While that's obviously sound advice, I don't think that you'll have anything to worry about.
Chris