there is absolutely do guarantee that the installation will take place on the new date or many more that might be given - thats the way of things with VM installs - the system is not broken it simply does not exist in any meaningful manner - it could happen or it might be months away
but whatever happens and you decide DO NOT cancel - you have an install date of the 11th March - compensation on £6+ a day starts then until they finally install you - if you decided that enough stupidity from VM is enough and you have gone elsewhere once VM install you cancel in the first 14days at no cost
if you cancel before then they will stop the install so if you decided in the future to give them another chance the whole install saga would start again
and if you do let them install dont let them con you out of the compensation wth their usual rubbish that they needed council permissions or the 11th March was provisional - if they take you down thos paths just ignore them and go to the arbitrator