Faulty Mattress - is this a joke?

I bought a bed and mattress from Coricraft about 15 months ago, The mattress I noticed started to dent in on the one side. I phone them a few weeks ago. The came to inspect it yesterday. The two gentlemen immediately when they walked into the room noticed that there was a problem with the bed. They sat on it and said that there is a problem with the springs. They filled out the report and left. I was contacted this morning and a lady informed me that they would not be replacing the mattress because it had a two coffee stains on it. I laughed I said is this a joke? I noticed the two small coffee stains but I mean it would have taken two minutes to remove it with soap and water. I asked her but what about the faulty springs, she said no its not their problem and sounded very smug , I still thought its a joke - then she got rather rude and I realised it was not a prank, but that it was blatantly obvious that they were passing the buck and looking for a easy way out. I cant believe that Coricraft would risk their reputation like this? My mind is saying to me this must be a joke?? Unbelievable.