Ist mythemeshop.com sicher?

Having used mythemeshop themes for a while both as a free and premium customer I was very surprised when they refused to refund me (within 30 days) for a particular purchase after the theme was missing some important functions and the support staff told me they wouldn't assist me via email. Not only did they refuse the refund of $59 but they also threatened to ban my account with them (which has at least one other premium theme I purchased currently in use and paying them $20/year). They literally emailed me saying if you open a dispute on Paypal we will ban your account! I'm sorry but this doesn't sound to be the kind of business practices in use by legit American businesses. A customer wants a refund you give it to them simple as that.. Especially someone who is still buying other services from you. I am currently trying to acquire a contact number from them so I can discuss things over the phone. All in all very disappointed by the tactics and staff employed by this 'internet' company.