Actually there are a few other registries that doing that same practice.
Domain Registry of America sent out what appeared to be bills to a lot of
my clients and they just routed them to their billing department for
payment.  I get the "your registry is changing" message and NEVER
acknowledge them.  Now I have to have clients track down payments with
their credit card or payment departments and then turn around and attempt
to pay the blasted bill.  *Sigh*  What I HATE is when you go to renew a
domain and Verisign has the two different rates, reseller and "end user".
I think we all know who really gets it in the end.  Ugh.