Can anyone help with the Natwest Bank, Gloucester, please?
0845 301 9754

There are 5 Natwest branches in Gloucester.  This is, I think, their main branch:

21 Eastgate Street
Gloucester
Gloucestershire
GL1 1NH
Sortcode
600902

24-hour telephone service 0845 604 1604
International +44 (0) 121 236 8837
Branch 0845 301 9754

If you call the 0121 236 8837 number which is in Birmingham, they will probably put you through.  When you dial the the number do prefix it with 141 to conceal the location you are phoning from.

Contact details for the other 4 branches are on the Natwest web site >>contact details>>branch locator. Even the 0845 number is shared with other branches so probably all go to a call centre initially.  The call centre will try to resolve your question and they will only transfer you if they cannot.