You should have received the mower back – he can’t claim for it and get a refund, then also keep it – he is basically having his cake and eating it. The mower should have been returned to you so that you could have then decided what to do with it – you could have repaired it, sold it as spares, etc. Having issued a refund for the faulty item, the customer would no longer have been entitled to keep it, unless you had agreed otherwise.
So at this stage you can make that clear to them and request that arrangements are made for the item to be returned to you. Remind them that if they fail to do so then you reserve your rights to make a claim against them as well for the return of the mower, or at least its current value which means that if they fail to return it and you win, then they will be ordered to pay an amount to cover its value and overall they will end up with a lot less compensation that they did.
Unfortunately it may be a bit late to involve the current court in this as you should have made it a condition that the money will only be paid on return of the mower, so once you have paid all the money for the refund, you may have to start your own claim to recover the value of the mower back.
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