Check the fine print of your purchase to see if your new mattress is covered by warranty or a guarantee and what is included, how long and what voids them.
This will provide a pro-rata benefit usually in terms of a discount off a replacement mattress based on how much of the warranty term you have used vs unused. So if you have had the mattress for 7 years from a 10 year warranty on that mattress, you are entitled to get compensation for the remaining 30% of the unused period.
Most warranties offered are usually in the range up to 5 years for bonnell spring mattresses and up to 15 years for pocket spring mattresses.
This benefit will provide a new replacement mattress right up until the last day of the guarantee period.
The period offered is much less than that of a warranty, usually in the range of 1 to 3 years for bonnell spring mattresses and up to 5 years for pocket spring mattresses.