Communication Mishap

I was worried when I spotted two cars parked outside my house this afternoon.  I only expected to see one.  I had arranged care for Merv with our regular service provider.  I was attending a carer training course for over five hours.  
I parked in the driveway behind the car I didn't know and entered my house. The regular support worker saw my distress and immediately asked if the office had rang me to let me know she would have a 'buddy' with her.  The answer was simply 'no'.  No one had rang or emailed me.  
A buddy is an experienced support worker providing hands on training to either a new support worker or a support worker requiring specialised training to provide a service for clients with specific care needs.  Many years ago part of my job description was to buddy support workers.  I know the importance of ongoing training and will always support and encourage training new workers.
It is sad and alarming that communication is not taken seriously in our community. Also it is just common courtesy for the service provider to let us know about any changes to Merv's services but there is a bigger issue here.  After the girls left Merv asked how many grandchildren we have.  I stood and looked at him. I was speechless. We have no grandchildren! We probably will never know exactly what caused Merv's disorientation. What I do know is; I need to return home knowing who is in my house and both Merv and I are agreeable to the service and how it is provided.
I was unable to contact the coordinator by phone and sent her an email voicing my concerns.  I am awaiting her return call.