A non-geo number for Mio-Tech is  0905 4640010, which is the number you had.

However, a geographic number is a bit more difficult. It would appear they operate from Brussels. So I assume they number they've given you connects to their Brussels HQ, possibly via VOIP.  Perhaps you could try International Enquiries.
However, looking through their contact numbers, it would appear that they all charge a premium, irrespective of country. So using a cheap dial through number to contact the CS of another country might not be worthwhile.