Why I had to talk to Grandma in order to make a vet appointment and other strange things

Unlike in the good ol' USA, here in Ecuador many businesses are family-ran. In fact it is very common for families to section off a portion of their homes to create an office or store. The part that is strange to me is that in order to make an appointment (with my orthodontist, the vet, or a potential site for our wedding reception) I have to call the house number, which means I usually talk to Grandma who is quite old and hard of hearing.  I'm not sure why Grandma is deemed the phone-answerer, but let's just say she rarely understands my foreign name, she called Andrés "señorita" one time when he tried to make an appointment for our wedding, and upon my phone call she usually yells for 2 minutes in order to get the correct person to answer my questions.