Why don't you want to do telesales? Not all telesales are tenacious annoying calls that disturb your dinner. Ask around for any landlords known by your contacts, ask your contacts to call them, then you call the landlords with their permission and ask them who they use as agents. Ask them how they find the service, ask them what problems they have.
I had a terrible fear of the phone but when it becomes desperate you just have to do it!
Have a look at networking organisations such as BNI and 4Networking. The point of networking is to find people who have the contacts you need, and many of the members of these organisations are private landlords themselves.
Good luck!