Make sure you always avoid hot water while washing your hair and use a mild formula type of shampoo. Ensure that the shampoo is recommended for colored hair, also avoid hot oil treatments because they are also known to strip color out. You should get more assistance from your stylist.
Ok, since nobody is telling you this I will. Red dyed hair is the most difficult color to keep in. You can do things to endure it's color like washing it with cool water. Also, after coloring it you can put in a sealant like clear "Jazzing." Jazzing can be purchased at Sally Beauty Supply. Sun also fades red colored hair, so you can buy a cream that protects it from the sun. Redken has a bunch of products. It's important to purchase color safe products at a reputable beauty salon. It costs more, but it's part of the upkeep of having red hair.