Can a seller refuse to give you the support you've paid for?

I have an adult site and I have a plugin + paid support with it.
I asked the support to help me about a small little thing and they refused because my site is adult. But I’ve paid for support. Can they do this? What’s their business with my content, why should they care once I paid? I mean, my problem is not even directly related to adult while the website where plugin is installed it is