Soldato
Because they can raise their prices. And it depends on your deal and the wording. If your deal is 'half price' or '£x off' then if they put the price up the price you pay increases. If your deal is a set '£10 per month' then even if they increase the price the price you pay won't change.
That is the thing though, I thought the "Affinity 1 + calls" promo was a set price of £10 per month during the promotional 12 month period, that we are only in the third month of since signing up. When we signed up, this would revert to £24 per month.
We paid 12 months landline rental up front for the savings (~£3 per month at the time), so any landline rental increases that happen before next July shouldn't affect us until our 12 months is up.
It is not a lot of money, we are only talking 65p per month, but on the face of it I currently feel it is a sneaky increase. Maybe I missed the big asterisk stating that the £10pcm promotional price is subject to any price increases for any Affinity customers.