Double matress (Wigton Moor LS17)

Bought this new a couple of weeks ago and its faulty in that it has sunk a little as in the pic and sometimes the springs make a noise so I do not want this but if anyone can make use of it please help yourself. The advertised details are below.

Product Features
Gel Memory Foam: A 10inch thick spring mattress with a 13-zone gel memory foam layer which moulds around the shape of your body to give you the best sleep of your life!
Cooling: This unique fabric has temperature regulating properties, too - the fibres absorb 60% more moisture than cotton and prevents humidity buildup and discomfort during warmer months.
For Side-Sleepers: With a medium-firm rating, this deal is perfect for those who like to sleep on their side, or those who prefer a little more support as they sleep.
Hypoallergenic: Features a luxuriously cool stretchable fabric cover which is hypoallergenic and dust mite resistant, ideal for allergy-sufferers!
Great for Circulation: This innovative mattress is also designed to relieve pressure points across your body to promote good blood circulation.
Eco-Friendly: Made with high quality organic fabric and water-repelling beeswax emulsions.
Made in the UK: This mattress is manufactured in the UK with quality craftmanship and premium materials.
Safety: Fully compliant with all UK fire regulations - so you can sleep easy!