After 3,000 miles when I turned the ignition on and pressed to 00 it would say I had approx 10,000 miles left. Now after 4,500 its says service now 
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Could it be to do with the oil lamp came on after 3,000 put a ltr of oil in and the lamp went of, now after4,500 the lamp did not come on but when i checked the dipstick it needed another ltr. Is it normal to need oil so regularly.
Oil consumption first: the acceptable manufacturer tollerance for oil consumption is upto 1 litre of oil per 1,000 miles - so you are clearly within tollerance.
Now, your specific issue. You were obviously on the LongLife servicing regime. However, two things to bear in mind.
Firstly, you will be personally awarded a certificate of muppetry. Why, you should NEVER rely on the warning light to tell you to top up the oil. There is a "thingy" under the bonnet, with an orange loop on the end of it. It is called a dipstick. Learn how to use it - regularly. You clearly are not using no where near often enough!
Lesson one over, now onto lesson two. By needing to top up with one litre in one go, you were basically running with a loss of at least 25% of your lubricant capacity. With such a dramatic loss in lubricant, the remaining oil will be subjected to much greater, more concentrated levels of stress, and will start to break down rapidly. The LongLife regime uses the oil quality sensor in the oil sump, and any degridation of the oil will noticeably forshorten the time/distance available to the next service.
Final Q: what type of oil did you use to top up with? If you used more than ½ a litre of non-LongLife oil, the oil quality sensor will pick this up too, and also reduce the service due miles/date.
