In 2009 we purchased a marine radar system from Raymarine with accessories from the GPS store that did not work as advertised. When we communicated the particulars to Raymarine, we got the run-around and even after writing multiple letters, did not get the satisfaction we sought. Our dealings with the GPS store were not much better. 

As of December 4, 2009, no written response was received from anyone at Raymarine, least of all from one of the parties the letters were sent to. We all draw our own conclusions from that....Caveat emptor - Buyer beware!