How big is the female? Have you or can you sex the snake yourself? It's possible that the female is too small to ovulate, or that they are both males (yes two males will lock up sometimes it's a domination thing). Or maybe the store manager thought it would be a selling point and is just jerking your chain. Also if you are just breeding normals then that would be ok if she was also breeding a normal male previously - but if you are attempting to put her in with a morph - she could retain sperm from the previous donor and you'll get normals. Depending on your confidence and plans you may have a good deal or not. If ou aren't in a hurry to breed this season then maybe a yearling/subadult would be a good idea.
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Tosha 
"One of these days i am going to wake up..look around...and realize my place looks more like "Ace Venturas"s than my own." Coldthumb
7.33.0 Ball Python (Harry and Fluffy and gang)
1.0.0 Angolan Python (Skywalker)
0.0.1 Green Tree Python
0.2.0 Feline (Pippen and Pandora)
0.0.1 Dessert Tortoise (Pope John Paul "JP"
2.2.1 Fish (1,2,3,4)
0.0.2 frogs rescued from pool skimmer
0.0.1 lizard rescued from vicious feline