I have a 1999 Z28. I recently lost my ignition key. I called my local Chev. Dealership. I gave my VIN number to the parts dept and was told that they had the right blank.
I subsequently went there and proved my ownership and had the key made ($99.23). The key will not work. When I called them, they (of course) stated that the car (Ignition) had been altered. It has not.
Is there anyone to whom I can appeal this arbitrary quick decision/answer?

 

Does the key turn and crank the engine over, but it just doesn't start (VATS issue), or key doesn't turn at all?
To know that nothing with the ignition has ever been altered, you must have owned the car since new then.

 

If the key doesn't turn, you may need a locksmith or a replacement cylinder.

If the key turns but the starter doesn't work and the security lamp is on, they used a key blank with the wrong resistor pellet. If they won't make a new one, you can find the correct resistor value (trial and error with 15 values) and buy a new blank for about $10. Then have it copied from the other new key at Home Depot for about $3.

One of the 15 possible blanks: New GM Factory Original Vats Single Sided Key Blank B62 P15 595525 26019405 | eBay

 

My key doesn't turn at all.

 

You didn't say whether or not you've owned the car since new. If not, it's quite possible a previous owner replaced the key tumbler assembly. The key the dealer gave you may likely have the right (1-15) resistor value, but the wrong cut. A resulting mis-match wouldn't be the dealers fault.

 

call a locksmith and have him make one. you will need a blank with the correct resistor/bean on the key.