Restonic Mattress

We bought a Double restonic bed from OK late December 2019. Three months later the matress is sagging. My daughter weighs 60 kg and the only using the bed. I know from experience if a mattress does that it was stored upright. The moment the lockdown was lifted to travel over the borders I contacted Restonic several times after OK furniture Potchefstroom also send a email to them. The first time they didn't even put the claim on the system. The second and third time they were full promises the new mattress is on its way. It is almost 2 months later since my last call and not even OK received feedback about this matter. I am very disappointed in this company.