Iva transfered to them and completed over 5 years ...

Iva transfered to them and completed over 5 years ago, ppi money then paid to them 4 figure sum which just disappeared, can't get in touch to see where this money went and was told it would be divided 80/20 when taking out iva. Don't believe any went to creditors as case closed .email they give on correspondence does is not valid and if you manage to get through to them by phone they just pass you on to different departments with no answers.