Home Depot Wood shrinkage after building deck Richmond Virginia

The first part of 2014 around March I bought deck boards from Home Depot to replace my aging deck boards that were split and popping up. The boards in question were advertised as 5/4 by 6 inch. I used the 12 foot lengths. I spent at least $725 including screws and sealer  for redoing the top surface. I bought the wood at different intervals usually 15 to 20 boards at a time. 

I installed the boards (with 2 screws every 16 to 20 inches across more at joints) butted as close to each other as possible both from the side and end to end. After about 30 days I noticed some gaps showing up between the boards where there was none at first.  Next, I applied Thonpsons water seal after the designated time on the container had passed over 30 days in full sun. A few weeks later, the gaps continued to expand to about 3/8 inch in some places. I took some of my tickets ( what I could find)  to the Home Depot on Broad near Dickens Road and explained situation. After considerable talk, the assistant manager allowed me a credit of $120 which I felt was really not enough considering all the labor involved.

Now, it is June and most of my deck boards have contiued to shrink to in some cases gaps of 1/2 inch and greater which along with the end to end gaps and warping leave a trip hazard at best, not to mention an unsightly mess of all my hard work. I trusted Home Depot to give me a reasonable quality product for my money and all I got was a big mess that I don't know what to do with. Some boards measure 5 1/4 inch which is in my opinion false advertising for a so called 6 inch which I realize will be some less for finishing the edges approx 5 3/4.

My deck is now a mess and safety hazard and I don't even want to look at it depressing to say the least.