Audio Voice Enhancement

I need a recording of two people that is muffled through a couple of walls to be enhanced so that the voices are made clear again. There is also a section of audio that is gone and needs to be recovered if possible... (Budget: £20 - £250 GBP, Jobs: Audio Editing, Audio Engineering, Audio Mastering, Audio Mixing & Mastering, Audio Production, Audio Services, Sound Design, Speech Recognition, Speech Synthesis, Voice Talent)