Wake up to that great Sealy feeling and BACKACHE EVERY DAY

On 01 May I ordered 2 x Lannister Plush Medium mattresses (1 x double and 1 x 3/4) which were delivered on 21 May. During October I logged an online complaint on their website as both mattresses had started sagging/dipping in the centre leaving the sides higher than the middle. A consultant called and advised that I should go to the store where I bought the mattresses so they could log the complaint. Also advised that she had sent me a mail with instructions which I had never received as my email address had been typed incorrectly. She subsequently resent the mail and instructions which stated to go to the store where purchase was made or alternatively to send Sealy the proof of purchase and invoice which I did. When I had not heard back from them days later I emailed the consultant who called me back and to say I needed to go to the store. When I queried why the email she sent said I could go ro the store or alternatively send them the invoice and proof of payment was informed that email was wrong. Why send an email with incorrect instructions to a customer? My husband and I as well as my 8 year old grandson for whom I bought the 3/4 mattress have all have been waking up and battling with backache since sleeping on the Sealy mattresses. What a disappointment as to quality, should have never changed to Sealy.