Header not responsive on iPhone

I loved the look of this theme as well as the fact that it was described as responsive across devices. I utilized the theme’s editing area to customize colors but I did not change any settings. The header (simply a pre-made box with the site’s name in it), which looked lovely on the computer screen, became squished up and overlapping on the phone’s browser. When I contacted Theme Junkie (the maker of the theme) I was told that they do not offer support for free themes. I told them that I would be happy to purchase a theme but that I was wary of the support I would receive given that their free theme neither does what it is reported to do nor will the creators of the theme fix their error. Needless to say I will be looking from a new theme from a different company.