Who governs occ pension?

tommytynan123

Made redundant last August and drew pension as lump sum - all worked as advertised. Received a letter from ex-employers on Dec 1st saying that during October an audit had revealed that their contributions over the 3.5 years of employment had been £544 short and the money had been sent to pension provider on 27th October. Nothing paid to me as at 1st Dec.

Called provider who said ''no record of receiving money and even if they had it would have been sent back as, with pension closed, they had no mechanism to pay to me''

Now being fobbed off by ex-employer who said ''the money was sent and due to a new project at the provider the money is sort of hidden but will reveal itself when the new project is implemented'' (No time scale)
I replied strongly ''the project at provider is not my problem and you (ex-employer) should now pay me direct and sort out the missing money when it reappears'' I've set them a deadline before I push further outside ex-employer.
Query is though - who do I go to next? ACAS? Small claims? Ombudsman?
Thanks