Please don't panic (at least it looks that way.. I think it's only harmful). I think if eXch is silent, there are reasons for it (and as far as I know, not a single request over the past years has gone unanswered... all cases have been resolved). Moreover, if you remember... I once suspended a campaign for several days because I did not receive a response from eXch for a long time, but despite the silence, their service works automatically, and their reputation is impeccable.