Wait one minute.
Are you saying that this stereo repair shop is keeping your insurance refund & only offering you some bs in store dredit? If so they are stealing your money plain & simple.
Here's how it works,ups has a contract with the shipper,in your case the shipper is the repair center,ups will only deal with the shipper,once damage is notice the reciever(you)call ups & report the damage then you notify the shipper(repair shop) & they inturn file a claim with ups for the full amount of insurance.
Here is where it gets tricky,ups will give you a bs story about sending your amp to some inspection center,there is no such place as a ups inspection center,they will tell you that they are issuing a pick up & are sending a truck for the amp,tell them in no way are they picking up the amp & that they need to send an on site inspector to look at the damage,this is very important,DO NOT THROW AWAY ANY OF THE PACKAGING FOR THE AMP,NOT EVEN A PEANUT,ups will make an appointment for their insurance companies agent to inspect the amp in your home,ups outsources their insurance for all items shipped.
If you allow ups to pick up your amp you can be assured 100% that your claim will be denied on the grounds of improper packing no matter how it was packed,by keeping the amp & forcing an onsite inspection you can show somebody in person just how it was packed,if ups picks it up their policy is to reject all claims,the amp will be shipped straight from your house to the repair center & the claim will be rejected.
After the onsite inspector from the outsourced insurance company makes his decision(on the spot) the repair center will need to fill out some paperwork then send it back to them,after ups gets the paperwork they will issue a check in the name of the repair center which should then be fowarded to you.You need to remember that the amp was insured on your behalf & that you paid for the amp & shipping.
If the repair center refuses to give you the insurance claim they are ripping you off & a store credit is not how it works.