Thank you for the question. In the letter you will want to show that you are not liable for these charges. So if you clearly set out the reasoning for this and include the letter you received, they will either have to accept your argument, or provide legal reasoning as to why they believe the VAT to be applicable. If you draft up a letter I would be happy to offer a document review. However so long as your argument is structured to show the reasoning behind the applicability of VAT you should be fine.
I shall provide you with a helpful link that will assist you in finding a solicitor/representative near your local area. This will provide you with someone nearby your area who can assist you if required.
I hope this information proved helpful. You will find a local solicitor who deals with these matters on the law society webpage which is as follows;
https://www.lawsoc-ni.org/solicitors (N. Ireland)
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