Promises not kept

We purchased two single beds from Mattress King. As a usual sales person will tell you it's the best on the market and how many years guarantee and if you have a problem we will attend to it come back to the store and they always end up with the cliche BUtT ull never have a problem. Well you know what it's only been 3 years since we have it and using it for only two. My young sons sleep on them. The legs have broken off from the base. We went into the store 2 months ago with the slip etc and they kindly told us someone will contact us. To date no one has despite going to the store AGAIN 2 weeks ago. My sons bed is on a slant for most of the day and when he sleeps at night it sometimes just goes to the side if he turns. This service is patethic after been promised twice that someone will call and come through. Can someone from mattress king please assist.