When installed and working, VM is fast and acceptably reliable, and there are some very good bundles and offers, but customer service and customer communication are firmly stuck in the dark ages. If you choose to wait this out you should get £5 a day credit for a delayed installation when your account goes live (some people have got several hundred quid of credit from this), but that may be scant satisfaction if you have to use a mobile data connection for several months - a number of intending customers have seen delays measured in terms of several to many months, due to a complete collapse in VM's processes for new connections and cable re-pulls.
You can of course cancel without penalty up to 14 days after the service is connected, so if you want to cancel now you can. Or you could make other ISP arrangements, let VM install, immediately cancel the installation under cooling off rights, and then if you decide to give VM another chance in future you'll have the physical connection work all done and ready to go.
Thank you for reaching out to us in our community and welcome back, sorry to hear you still don't have an active service, I have been able to locate your account with the details we have for you and can see a technician is booked for you, if you wish to reschedule or cancel this can be done via your online account here virg.in/myVM?