Poor customer service and mis.sold

I purchased a mattress set from the Phoenix branch in 2020 .was told at the time of the sale that the bed comes with a 10 year warranty.i recently had a problem with the mattress to whee the base collapsed so I claim for replacement of the mattress only to be told that the bed had one year guarantee and in order to claim back from the 9 years warranty .I have to pay a further R699 to be provided the 9 year warranty.which I feel is poor customer service and mis.sold at the time .I have called and spoke to the store person only to be told that they always tell customers that the bed has one year guarantee and not ten years warranty .I feel that this service is appalling and I should be replaced with a new mattress with no payment required