This happened to me recently and I can offer some important tips.
- Call the power company.
- Don't take "no" for an answer.
- Tell the customer service folks an electrician found a problem with the transformer neutral and he needs a lineman to inspect it for him.
- Call the power company again if you don't get a visit from a lineman on an emergency basis. By that I mean, within a day or two max.
- Expect a lineman to bring a SuperBeast or similar tools for testing your meter base and other connections.
- A lineman can't repair anything on your side of the service entrance, but should be able to eliminate all utility connection issues.
- If the problem is in your panelboard, you really need to get an electrician out there ASAP.
- In the meantime, if anything goes wrong with your grounding system, or if you have any ungrounded appliances such as a 3-prong dryer or a poorly connected furnace, there will be a severe fire hazard.