That's alot of garbage in the carb

Summit is very good at putting it back to the manufacturer, check your invoice to see if it notes the serial number which would have been printed on the box the carb came in bu the upc code, I had an issue with three MSD boxes that all had a problem with what they called "infant mortality"(MSD 6AL) and they sent me to MSD, they (MSD) took the boxes back and had them analyzed and sent me three new boxes the next week, Summit said it was because the manufactures warranty is "honored" through Summit, but if I deal with the Manufacturer directly, they would take care of any shipping.
Your problem seems like a individual store problem and would see if the carb serial number you have has been previously purchased, if your invoice has a serial number on it, this should be really easy to track, sometimes the stores get inventory from other branches, and that may be a problem. Let us know how it turns out, I don't think Edelbrock will do anything at all, but send them an E-mail anyway, they may make a phone call in your defense, especially if you tell them that you like their products and use them often, there is no way it could hurt (besides they might send you a T-shirt or something).