Just because there is no phone listing in the town of Vizovice does not mean that your ancestors were not from there. Some people do not have phone, some had it disconnected and have a cell phone. The young generation moved to where the jobs were The town of Zlin is West of Vizovice about 10 km apart. You did read that there is a Machacek listing in Vizovice's phone book?
I do not recommend phoning. It is much better to send a letter with family information, do include your e-mail and a photo of your ancestor for that extra visual aid.