Sometime grudges are good things. Verizon jerked me around for years on a DSL problem so I left. Got a smaller commercial ISP who was 10 times better CS and within a short time found and fixed the problem that Verizon refused to do.
Then Verizon kept calling to get me back. I said never. And I meant it.
We changed to DISH the next day and I truly love to confront DirecTV salespeople who prowl the Wal-Mart drumming up business.