Documents to be requested from plan sponsor

[Guest ALOHA]

I recently joined a company that participates in a multiemployer plan covering its union employee. The employer has been paying its contributions and was recently told by a representative from the plan that the plan was frozen and that they should continue with its contributions while it is determined whether contributions are increased or a "mass withdrawa"l is determined. I asked for Plan documents and other subscribed agreements but I am told that they don't have any. In addition to consulting a qualified attorney, what documents can we request from the Plan that supports the amount of contribution . Shouldn't the plan issue an ERISA 204(h) notice on the freezing of the plan. Any guidance to determine what documents the company can request from the Plan is appreciated.