LIVE from the Camino Getting a taxi on the Norte

Hello, my mom and I are walking the Norte currently and she has developed plantar fasciitis. She can walk some, but would like to bus or taxi some each day. I plan to walk as much as I can. What is the best way to get a taxi when buses aren't available? I tried to call in a taxi in Llanes and the call wouldn't go through, so she just ended walking the last few miles and ended up in great pain. I do have a Spanish sim card. Do I still need to dial the country code? Is it possible to call a taxi if I don't speak spanish? Are taxis expensive? Any suggestions would be helpful!