No response on claim and not getting through c/cen

I have submitted my gap cover claim the 05/06/2016. I have tried for the past week to do a follow up on my claim with the call centre without any success. Have been holding on for more than 20 min on 4 calls for 4 days now. First it is high call volumes then technical problems. Then they inform you to leave a message just to be informed that the mailbox is full and cannot take any more calls.<br> <br> Please sort out this as the doctors wants there money.