If you were on a Package Holiday, the Tour Operator is bound by the Package Travel Regulations and in particular sections 4-6. These oblige the Tour Operator to supply exactly what was brochured and if they do not, provided that you have sustained a loss or can show the problems it has caused you may be entitled to compensation.
Alternatively, you may have rights under the Sale of Goods and Supply of Services Act 1980 or potentially a claim for misrepresentation.