I am always happy to have parents call. And, as I'm sure I've said loads of times before, I'd rather have a parent call me than be asked to call them, because of the ****ing about, getting out of the room, getting the phone, getting child's file, digging your number out, then your work number, thenyour mobile, then your partner's number, leaving 4 messages, then waiting to get a call back. Much easier to be handed the phone and be told "it's Mel..."
I used to work with one parent who phoned us three times a day, and often cried when leaving her 15month old, which was awful to see but completely understandable. There were also mums who never called, but if something was wrong and we called them, they'd be there in 10 minutes.
We don't judge anyone who loves their child... if they arrive in a fresh nappy, clean(ish!) clothes, are fed and we're informed, then we're pretty well happy.
Because you're not seeing them, next time you call, ask them abotu a way you can better stay in touch. Maybe the communication book can travel to and from in Aricyn's bag? Maybe you can set a time of the day for you to call them? A good CCW will have some good ideas on how to do this.

Good luck!