Hi Nixxi92,
I don’t have a direct number I’m afraid I Just had to call 0300 222 0000 and asked to get put through.
I spoke to the customer service management team on Tuesday who said I was eligible to upgrade to fast track. The gave me a little speech, said they had made a note on my application file and told me I had to email the upgrade team within 24 hours of my call. The offer expires after 24 hours. If the time elapsed I had to go through the process again.
I was on hold for 2 hours 30 minutes!
Good Luck