Hi Manitoba,
I’m sorry to hear that the mattress you chose isn’t working out as well as you hoped for.
I certainly would be very cautious about exchanging your mattress for a major brand mattress. The major brands such as Sealy/Stearns & Foster, Simmons, and Serta all tend to use lower quality materials in their mattresses than most of their smaller competitors that will tend to soften or break down prematurely relative to the price you pay which is why I would generally suggest avoiding all of them completely (regardless of how they may feel in a showroom) along with any mattress where you aren’t able to find out the type and quality/durability of the materials inside it (see the guidelines here along with post #3 here and post #12 here and post #404 here).
While other people’s comments about the knowledge and service of a particular business can certainly be very helpful, I would always keep in mind that you are the only one that can feel what you feel on a mattress and I would be cautious about about using anyone else’s suggestions, experiences or reviews on a specific mattress (either positive or negative) or review sites in general as a reliable source of information or guidance about how you will feel on the same mattress or how suitable or how durable a mattress may be for you and in many if not most cases they can be more misleading than helpful because a mattress that would be a perfect choice for one person or even a larger group of people may be completely unsuitable for someone else to sleep on (even if they are in a similar weight range). In other words … reviews in general won’t tell you much if anything about the suitability, quality, durability, or “value” of a mattress for any particular person (see post #13 here).
Having said that … there is more about the Dormeo Octaspring mattresses in this topic and in this topic and a forum search on Dormeo and on Octaspring will bring up more comments and feedback about them as well.
It sounds like you may have purchased your mattress from Sleep country and unfortunately … like many of the members that have come here with a similar situation … you are in a somewhat difficult position where you need to exchange a mattress and may be “locked in” to a store or a specific manufacturer that sells mattresses that I would normally suggest avoiding in the first place and where there may not be any particularly good quality/value options available to you.
My comments to another member in my reply in post #2 here and the posts it links to has much more information that would apply to your situation as well and may be helpful.
If you did purchase from Sleep Country then assuming that you can confirm the type and quality of all the materials and components in their mattresses … their Natura mattresses or a softer version of the Dormeo Octaspring would probably be the only mattresses there that I would consider in terms of the quality and durability of the materials.
Phoenix