Sleepmasters mattress

We bought a new mattress from Sleepmasters Keywest Krugersdorp June 2024. Since the beginning of May 2025 we reported to the store that the mattress is sagging on both sides. We have been rotating the mattress every month. Now a rep came out on 12 May 2025 to inspect the mattress and he told us that we must spend more time in the middle even if you only play with your cell phone for a bit of time. Stupid advice. So Sleepmasters rejected our complaint and today after I asked the Keywest branch for an update they send me the report they already received 13 May and today is 4 June. One is not even allowed to sit on the side of the mattress otherwise it will damage it.??????? This is the worst mattress we have ever had in my 75 years of life. We are really not happy with the treatment we get from Sleepmasters as this mattress is not even a year old. Piet Kruger. Krugersdorp ***