Having tried other avenues I thought i would try this here. I have had my laptop for just over a year and last week as i moved it I noticed a crackling sound and only by chance happened to spot a spark coming from the wire that was plugged into the laptop. On checking further i found that the main cable was completely broken inside, as in the screw section of the cable, which revealed the three wires inside. Every single one of the cables had bare wires showing and were all within a couple of millimeters of each other which I expect could be extremely dangerous in terms of electrocution if touched to shorting the electrics in the house and potentially causing a fire. 

The laptop is not heavily used and for this to happen in just over 12 months is something that should not happen. I have HP laptops from up to 8 years ago that still have power cables that are in perfect condition. 

I feel this is something that should be replaced by Dell and something that should be brought to the attention of more people considering they could be sitting with a potential death trap in their homes. When you buy a laptop with a £1200 pricetag, you don't expect to have a fatally dangerous item  just a year later.