Having only being with VHA for 2 years I haven't even considered moving UP, but what I have managed to do is move across into new roles. Moving across is highly encouraged as it gives exposure to new skills and technologies, this removes the "silo" affect of only being knowledgable in one field.
Promotion at VHA is very probable if you are a consistently high performer. Often progression opportunities are unexpected. Living the Vodafone values and displaying good communication, team work and leadership skills are what it takes to move up the ranks in a general sense.