Advice needed about performing rights

We applied for performing rights to one of our one act plays ages ago. Following advice via phone, we used their email address.Anyway, we still have not received confirmation of rights ( or therefore prices ) . We have had to start rehearsals, enter festivals and publicise.The agents are ( of course ) overseas. They have not replied to numerous emails since. The receptionist can not answer questions over the phone.Any suggestions on what to do from here. ( Snail mail is an option of course, but it was THEIR request we use email ).Kimberley Shaw