The phone operator for Channel 4 quiz show Deal or No Deal, which is hosted by Noel Edmonds, has been fined £30,000 for misleading viewers.
Deal or No Deal won best daytime show at the TV Choice Awards
Premium rate services regulator Icstis has also reprimanded iTouch for breaching its code of conduct.
Viewers were led to believe that by entering the phone-in competition, they were in with a chance of winning one of three cash prizes.
Producers knew which amount would be won because the show is pre-recorded.
In its adjudication Icstis said "at the point of calling viewers will consider that any one of the three amounts is available to be won and will enter the competition on this basis".
Icstis ruled that although its code of practice had been broken, "the detriment to consumers from this specific breach was not high".
iTouch refused to comment on the matter.
The regulatory body also said the competition's promotion "increased the perception that the programme was live.
"This may have led some viewers to participate in the competition when they might otherwise not have done so."
In a statement Channel 4 said it was "surprised" the promotion had been ruled as misleading.
"Legal advice reassured us of its compliance with the Icstis code of practice and earlier this year, we discussed the mechanics of the competition with them," it said.
Channel 4 said problems with premium rate services were uncovered during its own review.
The broadcaster said: "Although all entries were always taken into account and had a chance of winning, we brought this issue to Icstis' attention as soon as we were aware of it."
A new series of the programme starts 13 August. Channel 4 said it will include a "new, fully compliant competition mechanic".
Earlier this month the channel announced a share of any profit made by the Deal or No Deal competition will be donated to charity.
All other premium rate competitions have been scrapped.