Nothing to do with their terrible shops?
I've bought two contracts in Vodafone shops in the last year, and both went wrong.
The first they packed me off with a PAYG SIM for a pay monthly contract, and I send ages with Tech Support trying to get the SIM working before they figured out it was the wrong SIM type.
The second I was sent away with a SIM and number which, I discovered when I tried to activate it, were not actually registered against my account. So I had to head back to the shop for them to replace the SIM and update my account.
Both times I had to use Vodafone's Chat Online option to diagnose the problems, as you're apparently no longer able to speak to anyone via phone - it does the job but it takes so long to get anything done. I can't believe it's actually saving the company any money.