Business Data Partners Graduate Program interview questions

I applied online via the company's website. I was invited to do online verbal and numerical tests. Pretty standard questions. Upon the completion and within a week I received an email from the company's HR which informed me that I was successful and that I would be invited for a 30-min Skype interview with their HR partner within a month. However, 3 weeks after I received a new e-mail that they will not process my application further since I my online tests were unsuccessful. I sent them an e-mail to question their responses with their previous e-mail as an attachment. Instead no one answered back to me. Pretty unprofessional behavior which made me question how unreliable and shady their hiring process was.