Contacting Professors

I'm trying to contact a professor from a university I'm really interested in applying to for Masters. I've emailed him twice now being professional of course but it's been more than a couple of weeks to a month. I'm a bit apprehensive at this point because they would've been extremely helpful to talk to. I'm thinking of calling them on their number provided in the staff directory. I just want to ask if it's appropriate and if not I won't, I just wanted to make sure. I don't want to be intrusive and annoying.

A question, why are you contacting this specific prof ? Is this someone officially in charge of admissions for the MSc you are interested in, or a potential project supervisor you might want to work with ? If it’s an admissions team point of contact, then there should be other staff associated with the MSc you can contact (e.g. a lead administrator) in case your target academic is out of action for some reason.

If it’s a more general “out of the blue” request then it’s important to know that Senior academics really don’t “lose” emails, if you have tried to contact them twice with no response the reasons are likely to be ill/on leave, your request is so far off point that they don’t think it worth responding, they simply don’t want to respond or you are asking for something unreasonable / unobtainable (e.g. full funding) that they don't have a polite answer to. In this case phoning is not the way to go, best to drop an email to their research group secretary enquiring if they are available / on leave and explaining why you are trying to get a response.