Upright Vacuum cleaner (Market Bosworth CV13)

This is a Dyson Stick Vacuum cleaner which comes with the box and all of the attachments and wall mounting Charger. It is red in colour. The only thing wrong with it is that it isn't picking up very well. I have put a brand new filter in it but it doesn't make any difference. If anyone has any experience of these they would be welcome to it.