What you need to know about this is here. Suggest you have a read thtough it and report back with any questions.
http://www.direct.gov...g/Tenancies/DG_189120
Your landlord appears to have failed you for at least2 reasons:
1) He was obliged to tell you within 14 days of the setting-up of the original tenancy which of the schemes he had registered your deposit with.
2) Within 10 days of the end of the tenancy he was obliged to tell you how much of the deposit (if any) he was proposing to hang onto.
You will now need to take him to court.