Judging by the number of long running pre-installation issues reported in the forum, VM simply don't care enough to put in place a process that works quickly and reliably, and provides easily accessed honest, accurate customer information. Even when you get info out of the company, there's a willingness to attribute delays to council permissions when the real cause is actually VM's broken processes. The forum staff are in a particularly difficult position, trying to get information across the intensely siloed and hierarchical structure, having to chase colleagues who don't respond, and everybody held back by systems and business structures that are not fit for purpose - and all the while put on a "company face".
If you really need VM's service, you'll have to sit it out and wait on the company, and hope that you'll get compensation.
If you don't truly need VM's service then I really regret to say it, but I'd suggest you speak with an ISP that puts more emphasis on customer service, see how quickly they could connect you and at what speed. Ask companies like Zen Internet, Aquiss, IDNet, uno or CIX, because they're more likely to be honest and give you clear answers on provisioning and speed than the large companies, and they are better at getting good service from Openreach than the big companies. If you want a TV + internet package then you're looking at BT or Sky who aren't as good as those smaller ISPs, but have marginally better customer service than you know who.
https://www.ispreview.co.uk/index.php/the-best-uk-broadband-isps-ispreview-editors-pick
The real root cause here is that twenty five years of unassailable speed advantage in the market has left VM bereft of the ability to compete. Why invest in customer service and related systems when "being faster" was, and briefly still is all that was needed? With the dawning of widespread FTTP roll out, VM are not displaying survival characteristics, and I reckon they have about 18 months to sort this out.
