Lack Of Service with Instant Money query

Hi, I sent myself money on Monday as I left my bank card at home. There was an issue with the ATM and I was unable to get the money. I then put the pin and voucher again and it told me that the voucher number has already been used. I sent an email to instant money and I got an automatic reply that someone will get back to me, the Tuesday I called instant money and I got a reference number for my query with a promise that someone will call me back. no one did. I sent a tweet to instant money on Wednesday and still no reply. I want my money back as I am unable to get through to your call centre since yesterday the whole day and still today I am unable to get through to your call centre.