Although I'm not familiar with your bass, your cheapest option (assuming the pups are passive) would be to wire the bass up passive in the short term - until you have enough dough to put an active eq in.
Assuming it's a 2 pickup bass - you'll need 3 pots, some wire, some solder and a capacitor. Do a quick search for wiring diagrams, or find a mate who can do it for you. You never know - you might even think it sounds better passive.
If you don't like it passive, once you've got enough money you need to decide whether to replace the original eq, or upgrade - I guess most of us would upgrade - so look at EMG, John East, bartolini, Aguilar etc.
If you have some front, you might take your bass back to the shop and ask them to fix it - they probably have a luthier they regularly use - insist on cost price as it's only just out of warranty, and insist they lend you a bass (prob second hand) to use while yours is away. be polite but firm - they want your continued custom........but maybe you bought it online or from Sound Control?
Just some options for you dude! Hope it helps.