2 days after buying my car, I get a warning light ...

2 days after buying my car, I get a warning light on. I brought it back in, and they were able to figure out what it was, and said they ordered the part, and would fix it, no charge. 2 weeks later, I called back to check on it, they said the part was on its way and they would call me back. That was 2 1/2 months ago.