Bailiffs and banks will not stop until it's sorted out, even in the case of a mistaken identity. It can make things extremely difficult, from as simple as getting a mobile phone contract to as important as buying a property or getting a loan. Your credit record can go "bad" without your knowledge through this kind of thing. There have been cases where owing £10 on a mobile phone bill 10 years ago has caused a house purchase to fall through.
This situation can often arise if someone in debt moves house but doesn't notify the creditor, then the innocent new occupier of the house gets hounded.
You can check your credit record for free online on Experian and a few others https://www.experian.co.uk/
. This should reassure you that you're not the debtor, or if you are in debt for any reason, it will give details.
Explaining that you are not that person will have no effect on these morons. Ask Wescot who the money is owed to, then contact that company as a priority to sort it out.
If you're unsure of anything or struggling, you can contact the Citizens' Advice Bureau or take a free 30 minutes with a solicitor.