If you are still employed, you cannot roll the account over unless there is an in-service provision to do so. Until WF is otherwise notified by the employer or the employer's representative, you are considered employed. Their responsibility is to their client, the company.
If an entity holding money in a trust for you, such as a property manager, goes bankrupt, the release of the funds to you can take years. I know someone that waited over 2 years for security deposits to be released. The bankruptcy court had to verify the deposits were in a proper trust account and not comingled with the estate assets. Then they had to notify everyone with the slightest interest and hold a hearing. All this for a couple of thousand dollars in this case.
A 401k should be much easier to resolve, but it's not likely to be at the top of the trustee's "to do" list. In your shoes, I would try to track down the company. If it's in bankruptcy, call the trustee's office. If it was in bankruptcy and the case has been discharged, it still might be worth a call to the trustee's office to see if they know whether there was an order issued for the 401k. Otherwise, you can call Wells Fargo and ask what paperwork they need and from whom to get this resolved.
If all of this fails, you may want to consider consulting an attorney.