We get a LOT of people who do something similar to you, or just leave their voicemail box full, or don't bother to set up voicemail at all. Then they get angry at us: "Why didn't you call me to let me know my system was finished?" "We did, and you didn't answer." "Oh, I don't pick up calls from random numbers." Well, I don't know what to tell you, then...
I can't text you, because we don't have a business cell phone to text with. Yes, I suppose I could set up some fancy integrated-with-our-POS system to text you from some number that we could then read replies to, but that both would cost time and money to develop, and would open up yet another vector for us to be contacted by (we already have a phone number, Yelp messages, Facebook messages, and email as it is.)
We can (and do) email customers, but email presents its own issues: People like to reply to them and we don't always have time to respond quickly, and people don't check their email often, or it goes into a spam filter...
It's not just us. It's your doctor, your pet groomer, anyone who has a local business. My suggestion here is to pick up calls from your local area code, and/or program into your phone the businesses you do business with.