With the store changes over the past few months, it is not as easy, but refunds are possible - especially if you are clear that the publisher of the product either defrauded you or broke the feature and refuses to fix it.
If the Ark team continues to ignore this, the BEST recourse is to issue a formal complaint to Microsoft, and they will get involved with the Ark team/Wildcard directly. (Which will force these to be fixed.)
I'm not sure what your beef with MS is, but when it comes to supporting users/customers, they will fight, even pursuing litigation on behalf of users. I 'get' that there is a popular myth of Microsoft not being good to users, and it is just a bit of FUD and myth. (Look at consumer rights, privacy protections and other litigation and legislation, it is often Microsoft alone that stands on the side of the consumer, and often against other tech companies like Google and ISPs like ATT and Comcast. Do a web search, and maybe use Bing, Google tends to filter unflattering stories about them.)