get the bailiffs in, but dont be surprised if the bailiffs say there is nothing of value to sieze.
You next steps after bailiffs are to secure a charge against an asset (like a house), and then force them to sell the asset to pay your debt, or initiate bankruptcy proceedings against them.All these routes are cheap and easy to do, they just require your time.
Its a long slow process, but in my experience you will get paid, it’ll just take years (literally) to conclude if the other person is insistent on not paying you.
The CCJ will usually do the trick , but it will take time for them to realise the effect the ccj is having on their business , ie having a ccj means that most will not lend to them, but they may not realise this until they need to borrow some money, and its at that point that they will suddenly pay you.