We can receive SMS replies at the virtual Twilio number we use for automated notifications. We have an amazing virtual team of volunteers and interns who reply to those messages in various languages - we actually end up doing more support for borrowers via SMS than email.
Most Zidisha borrowers own feature phones, but not computers. When lenders post comments on their profiles, we send the comments as an SMS text to the borrowers' phones. The borrowers can then opt to visit a cybercafe to post a response.