402(g) Refund not processed by employer

Hello - I notified my 401k administrator in February that I needed to remove excess contributions from the plan (I had contributed to two different plans through two different employers.  Administrator confirmed in March that the refund would be processed by 4/15.  The refund still has not been processed, and I can't get an update from the employer.   it is preventing me from filing my tax return, and I am also concerned I will be double taxed on the amount despite having provided sufficient notice and received confirmation that the distribution would be processed timely.  How can I get this resolved, and is this an ERISA violation?