More to the story than you are letting on. The cops don't have a warrant and aren't going to arrest you. If indeed they had a "signed warrant" they cannot make the decision to "give you a chance to do the right thing". Regardless if you refund all the money or not, there is still a signed warrant that isn't going to just 'go away' because you decided to be foolish enough to refund any money at all, which would be an admission of guilt in any court.
Let them arrest you, hell, you'll be out in a few hours and then have a lawsuit filed for false arrest, and against whoever signed this bogus warrant. That is, unless you have other skeletons in your closet that woiuld keep you in jail. That would be the only reason in this situation to be worried.
Bottom line is you need to go down and see the signed warrant (and just who the hell signed it anyway?) and proceed from there. Make sure you have about $500 cash on you so you can bail yourself out if need be and walk right in that station. It would be wise on your part to have an attorney on retainer already (and if you are the business man you claim you are, you should already have one) and have at it. You do have the cops name and badge number yes? Because for him to do what you claim, he won't be a cop much longer. The cops tend to frown on extortion, which is what this is. It is a scare tactic only.
Oh yeah, wheres the proof of fraud? You have a contract with Dish yes? Well then, there you go. Who did the "detective" speak to at Dish? There is so much wrong with the story, it just reeks.