0800 408 0009 is the silver freefone/tollfree number.

Blue, Bronze, Silver and Gold all use the same geographic number. Only GGL is different.

From ba.com:

Blue - By phone Tel: 0844 493 0 747 (from the UK) +44 191 490 7901 (outside the UK) Fax: +44 (0)1787 881405 Mon-Sun 0730-2000 hours

Bronze - By phone Tel: 0800 597 7580 (from the UK) +44 191 490 7901 (outside the UK) Fax: +44 (0)1787 881405 Mon-Sun 0730-2000 hours

Silver - By phone Tel: 0800 408 0 009 (from the UK) +44 191 490 7901 (outside the UK) Fax: +44 (0)1787 881405 Mon-Sun 0730-2000 hours

Gold - By phone Tel: 0800 123 111 (from the UK) +44 191 490 7901 (outside the UK) Fax: +44 (0)1787 881405 Mon-Sun 0730-2000 hours