Is there a way to call foreign numbers for free?

No idea which countries you are targeting but English speaking countries have very informative websites, you just have to dig a bit to get the part you need. Continental European universities can have pretty sparse information in English but you are not going to get much more information on the telephone if you cannot speak the language.

But if the cost of phoning is a problem, you should rethink the foreign university idea. All foreign universities are going to be far more expensive than staying in the UK. Even in European countries where there are only nominal tuition fees you will have out of pocket expenses such as your accommodation and travel that will not be covered by the student loans scheme.

If you have a telephone plan that allows unlimited calling, you can call them for free. Otherwise you can't.

yeah

VOIP