Advice about my new mattress

[Kai63]

We recently bought a new mattress from John Lewis (the Natural Collection pocket spring mattress with 1450 springs). We use it on a new sprung divan base.

It's advertised as medium support but it doesn't feel it at all. We've had it for four weeks and turned it as required but I wake up with lower back pain every morning and it just feels too soft.

We were advised to get a medium support mattress as both my partner and I are tall but slim build and relatively young.

My question is will we get used to it over time? We have the option of returning it but I'm not sure whether we need to give it more time. We are both used to sleeping on medium support mattresses but they have been cheap rental property ones (and still felt firmer than this one does).

Is it better to go for a small independent retailer and if so, what type of pocket spring mattress should we go for?

Any advice would be much appreciated!

we purchased a JL mattress about 6 years ago, it was a medium 5000 natural collection. After about 2 1/2 years it started to get dips and we complained. They sent out an inspector who agreed that it was faulty and they offered us compensation. We upgraded to much higher spec 10,000 spring count. It was, like the first one, lovely at first. But again, after about 6 months and regular turning (like every two weeks) it formed dips where we slept. To the point where there is a massive "hill" in the centre of the mattress. My hubby is 13 1/2 stone and 6 foot, and i am 8 stone, and 5 ft 1. We are hardly overweight ! My hubby wakes up with lower chronic lower back pain from where the dips are bending his spine, by lunch time the pain has gone. And then the next morning it starts all over again. We are in the process of replacing this mattress again. It is clear to us both that the filling in this mattress compresses over time, and causes the dips. It may be the springs possibly, but after spending over £2200 this is a massive disappointment.