Let's put this into context.
Let's say you have spent $2000 with them for hardware.
We'll be generous and say they are making 10 percent profit, so they have made $200 from you.
They sold you a fish which cost them $350 for $400, so they've made another $50 from you.
So far they have made $250 from you as a customer (which does not include their cost of overheads like rent, staff, etc)
The fish died.
You expect them to buy another $350 fish and give it to you for free??
If they do, as a customer you have cost them $100 for the pleasure of your business.
That's not how a business works, at least not for long ....
Be happy they are offering you any discount.