That’s the most ridiculous thing I’ve ever heard. You have to laugh at what clients say sometimes.
I did have one lady wear skin tight jeans after and the inside of her legs was totally gone where she sweated/rubbed but it wouldn’t happen all over. My lady was genuine and was still coming back for tans when she mentioned it.
Anyone tries this again you ask for a photo of their tan line area in the first instance and that will be your proof. And you can say ‘wow looks great, it’s come out as expected at x percent we agreed.’ Usually they need some sort of confidence building, especially if they are used to being orange.
You offered a solution (respray) and she said no, so obviously she is still tanned. I’d have asked for this refund to be in person that same day so I can see for myself.
Anyone that even mentions the word suing or legal action you just don’t speak to them and definitely don’t use messaging if you do. If you do then they will have it as evidence against you. Never say ‘I’m sorry.’ As that is accepting liability. ‘Oh no, is there anything I can do to help’ is better. If they say it again or do anything rash then you say ‘I’m afraid that because you’ve said you will be taking legal action I’ve been advised I’m not to speak to you about it.’ Which any solicitor would tell you.
But never worry about being sued as unless you have someone at your door with a signed for document it’s not happening. You have to have money to sue someone, which means if you are so poor you need a refund on a tan it ain’t happening.
If it’s between a few quid refund and a rant or bad review on the internet I’d take the hit and give them the money but not have them back.