Her's an idea - sue him for the amount of money you have so far paid over which represents what he should have paid. Dont bother with a solicitor, just issue the summons yourself on form N1 and pay the fee. Let him file an answer if he can, if he does not, then you get judgment in default and move to step 2. If he defends and there is a hearing, I doubt that the Judge will have much sympathy for him particularly if you produce evidence at the hearing of his liability and show that you have been meeting his liability to keep a roof over your head. When you win, move to step 2(posted 8358 days ago)Step 2 is to issue either a garnishee against his bank which siezes money in his bank account, but you need to time it so his wages are in when the garnishee gets to the bank in which his account is held. Or alternatively apply for Attachment of Earnings against his wages.
All these steps can be taken by the lay person, you dont need a solicitor - see your County Court staff for all the forms and helpful booklets and do it yourself. Court staff will not give you legal advice but will help you get the paperwork right.
I dont mind if you contact me by e-mail for further help if you want.