We asked them several times to stop calling, finally blocked them and filed a complaint with the FTC. I encourage everyone else to file a complaint with the FTC, they are blatantly disregarding the Do Not Call Registry and requests to stop calling.
They are trying to sell an extended vehicle warranty. IF GMC is behind this, you can bet this will be the last GMC I buy.
When I answered they hung up. I assumed they did that to verify that it is a working number. I had my number for 40 years. We are on the do not call list