We're really sorry to hear that you didn't like the bar, but most probably the confusion was caused by the fact that it is not dark chocolate. It is so called 'dark milk' or milk chocolate with high (65%) cocoa solids content. Although it contains a lot of cocoa it remains to be milk chocolate. It will never taste like 70% dark chocolate.
It also feels a little bit unfair to compare it with Cadbury. While Cadbury Dairy Milk includes MILK**, sugar, cocoa butter, cocoa mass, vegetable fats (palm, shea), emulsifiers (E442, E476), flavourings MILK SOLIDS 20% MINIMUM, ACTUAL 23%. COCOA SOLIDS 20% MINIMUM. CONTAINS VEGETABLE FATS IN ADDITION TO COCOA BUTTER Bonnat Contains just 3 ingredients - cacao, sugar, cacao butter, milk powder. The cocoa solids content for Dairy Milk is 20% and for Bonnat is 65%. The difference, as you may notice is drastic and puts Cadbury in a very shaky position.
Bonnat Morenita won Bronze in milk chocolate segment at International Chocolate Awards in 2017.
Hope it helps to address some of your concerns.