No response to emails

I submitted a repurchase instruction, on the 29th of June 2015. And I never received a response to date, although I was promised a response within 48 hours.THEY cannot say that the communication was sent on another email address because I specifically put this email address on the form I sent. I then sent an email last Thursday on the 9th but was never contacted again. Why must I keep following these guys up all the time?