Impossible to get in contact with anyone from RCS

My account was settled in Oct 17 and my debit order still went through as per normal. Now a refund is due to me. I've tried non stop for the last 5 working days to talk to a RCS representative but all I ever hear is......... "we are experience unusually high call volumes, please try again later or hold". Now I've tried calling later for the last 5 working days, varying from 8am to 5 pm without any luck and I've stayed on hold for more than 20min each time. After it became very clear that RCS telephones are unmanned I've resorted to sending a message on the RCS webpage explaining my dilemma, but no luck, why would they answer a message on email if they don't even bother to pick up a phone. It's so unfortunate that I have to resort to hellopeter in desperate hopes of any response. So, Mr.RCS, can one of your 2 representatives working at your call centre please get back to me or will I have to escalate this even further in hopes of any sort of assistance.