Bad service

I laid a complaint about the poor service of sealy from their headquarters on the 16th of Jan 2025 and was called immediately and inspectors came after 2 days to assess the bed.on the 21 Jan 2025 I was called and promised that they will arrange exchange of mattress with Bradlows (mind you it's the second exchange of mattress)within 5 month's of purchase. I've went to Bradlows more than 3 times and when they check on their system they don't have any authority to exchange my mattress. I'm sleeping on a sagging mattress yet I bought a bed 3 month's ago It's like I'm not normal going to that store and being told 1 thing. There was no reference given to me to produce at the store as I was told everything will be arranged with the store. What should I do now sealy? You refused to upgrade me after all these struggles and still you don't want to exchange either