There is no way around it
I remember a class on surveys years ago talking about the bias in surveys. I really don’t think it’s possible to make a survey without some sort of bias built in. Many bias that are built in are things that most wouldn’t even think about.
To participate on a phone survey it implies that a person has a phone, internet surveys are for those that have access to the internet and know how to use it… Even the census relies on being able to find people and get their information. Sending someone an online survey to…