Many countries in Europe have MVNO's with fairly decent prices directed at the local immigrant community. Because the immigrants come from many countries, they frequently have websites in English as well as the local language. They also have customer service in English and also usually voice prompts in English.

In addition to being able to deal with them in English, they frequently have very cheap international rates - sometimes cheaper than their own domestic rates, and usually much cheaper than the non-MVNO carriers.

Lebara and Lyca Mobile are two of these companies, and they are both in Spain (lebara.es and lycamobile.es)

When looking at their prices, you need to take into account any bonus they may be offering on topups. For example, last time I looked at Lebara Spain they were offering a 100% topup bonus - so a 10 EUR payment would add 20 EUR to your account. With a 100% topup bonus, your effective rate for calls is actually half what is shown on the website.

Also, they tend to offer free SIM cards - you can order online and it will be sent to your hotel. I believe you still have to then show up somewhere with ID for activation.

One thing to watch for when comparing Spanish mobile rates is that practically every carrier has a per call connection charge. So, you may see a rate of 1 cent a minute, but there may also be a 29 cent connection charge. This is all usually disclosed on the website.