Poor service from Mattress Firm

On 15/7/2015 I purchased a b/set and paid R4499.00 cash. Beginning of Dec 2015 I reported to the shop that the bed was sagging. I was promised that the area manager would come view my complaint in that week. On 15/12/2015 I called at the shop abot my complaint and stood by while the salesman contacted her and she made another arrangement. On 21/12/2015 I again phoned as the appointment was not met. He then gave me her cell no. She was rude, unhelpful and had no concern for my problem. Told me I had to understand she is busy and had forgotten. this is the written correspondence) I had to call on your shop for any follow up / arrangement to be made with regards to my complaint, after which an appointment was set for this morning at 10h00. The sales person directly me directly to you to follow up on why the appointment was not met. Your words to me where that you only looked at your phone when I called you. How was the arrangement for today then made? her reply was that the supplier would see me the first week of January. Till date this has not happened. I have an unusable b/set which is in a terrible condition