To me, a negative response says "We have evaluated our policy and decided that we will not stop this." A non-response says "A frontline agent didn't know how to make a call on a non-downtime ticket from a non-customer so now it's in a bureaucratic black hole and nobody has actually read your email and probably never will." Which is still crappy, but not really malicious in the same way.
No response is a response and in this kind of situation it is explicit "I will not do anything and I'm dishonest enough to not acknowledge that.".