Hi Tim
There are a number of Carrefour hypermarkets in the area, two in Murcia and two Cartagena. The ones in Murcia are sign posted from the Ikea roundabout, but it is still not easy to find. If you know where ikea is, there are two complexes either side of the A7 motorway, Eroski and Leroy Merlin to the north and Ikea and Thaler (this is the name of the shopping centre) Which has all that you want, to the south. There is a new shopping centre in Cartegena, which has a lot to offer, including Carrefour and leroy merlin, if you go down the A30, as the motorway bears around to the right before going into Cartegena, you can see it off to the right, it will be sign posted as an industrial estate, there will be sign posts for carrefour. The shop Gines Navarro is easy to find, head south out of polaris towards Mazarron, go all the way to the end of the motorway and at the roundabout, go left. Go along this road for 3/4 mile at the next roundabout go left again, at the next go right, another 1/2mile or so go over the roundabout, past Puerto mobel (this has a lighting dept at the back and will deliver install) and the tomato packing warehouse and its the next one along on the left, the local brits call it B&Q.
Hope this helps
Mark