you do not say where you are based but we had a lot of hassle from telefonica so decided to go for internet and phone connection via satelitte provider
we are with skynetlink based in Catrall near Almoradi, we had a few HICCUPS with them for the first week or so but are now very happy with their service.
We pay 25 euros a month plus calls. 20 euros is internet 24 hours a day, no extra, other 5 euros is for phone. calls are approx 3cents a minute to spanish and english landlines.
you would need to ask what rate calls are charged to mobiles.
there phone no is 965 990 969, you can access your phone bill online at www.skynetlink.es
Good luck.