Milly
If your car was on HP then it could well happen that it could be repossessed without a Court order - it depends on the circumstances and how much you had paid. If that was your situation then the people who came were not bailiffs - whatever they told you.
For a normal credit debt, if there has been no CCJ (or, in the case of council Tax, no liability order) then bailiffs cannot be involved & no goods can be taken. Anyone who comes has no powers & cannot do anything.
stephen2504 needs to take advice, as has already been said. If Payplan are acting for him then they should sort this out. If they refuse then he should go to another free advice agency (CCCS, CAB, National Debtline)