Welcome to the customers help customers Community of Vodafone.
At Vodafone you can take out a 1 year subscription and a 2 year subscription. At Ziggo you can only conclude a one-year contract and if you want to stop then you have 1 month's notice period. After the Ziggo year you can stop every month! The only thing that will change after 1 year, if you no longer have Ziggo, is your discount with Vodafone, which will then expire, and the extras you receive with Ziggo will expire.
My advice would be to go with Vodafone for a year subscription. Then you can always watch what you want after that year. Well, I would. So Vodafone and Ziggo for 1 year and then look back at what you want to do. Perhaps Ziggo is in that area or another provider has a good offer.