I'm reliably informed that you can contact the Data Protection Officer at First Great Western directly with your SAR (Subject Access Request) who's details are as follows:
Robin Williams
Data Protection Officer
First Great Western
MH22 Milford House
1 Milford Street
Swindon
SN1 1HL
There is also a direct email address which is fgw-dpo(at)firstgroup(d o t)com
E-Mail Address modified to reduce risk of spam bots
(at) = @
(d o t) = .
This I'm told will be a much better route to get the data you require.
I can only repeat what BNM has said.
I would use recorded delivery purely so you know when they received the request.
Ahem!! I said that!!