You have the right to terminate your contract with them due to their countless and recorded examples of their failure to carry out their responsibilities of the contract.
Personally i would do this without the cost of a solicitor as it seems from what you say to be a cut and dry case of their failure to meet contractual terms......
There is no great incentive for them to fight it either, Im sure the fees are not more than 1/2k p/a and losing clients, Im sure, is a regular occurance for them if thats their carry on..