Lost set of hired radio equipment and then refused to pay for it

She hired a set of walkie-talkie radios from us in May 2016 for a wedding show. She claimed that she had sent them back to us, but they never arrived and she has refused to pay us for them.
She is very evasive on the phone, the only way we could ever get her to talk to us was by using 141 or calling from a mobile number that she would not recognise.