When you move or your contract is up, investigate what your options are for services like cable. Find all available providers. Check their internet prices, then call for a phone quote (often they are different.) Tell them about deals you've seen; often they will then offer to match or beat it.
Be very nice when you do this! Often phone reps can offer you a better, unadvertised package at their discretion to get or keep your business, but they won't if you're rude or pushy.