Father scammed in Turkey by being charged £1500 instead of 1500 Turkish lira

As above. We were in Turkey and have just realised that my dad was charged £1,500 in a clothes store rather than 1,500 Turkish lira. I was separated from my dad at the point of paying by being gestured downstairs to look at something for my young son. My dad has Parkinson’s and became confused and felt pressured to put in his pin, despite not having his glasses on him. Is there anything we can do in the way of chargeback or through his travel insurance? He paid via a visa credit card with Nationwide. Thanks for any advise. He’s distraught.