How did you place the OTS request?
When it was placed you should have received an email/text message from the losing provider (EE in this instance) advising ot any early termination fees or the impact of the switch on any other services you currently receive. Did you receive this information from EE?
Did your EE service also include a TV service?
One of the problems is that the OTS process only covers landline and broadband. If the customer that's switching also has a TV service with the losing provider then the customer needs to contact the losing provider (EE in this instance if you had a TV service with them) to cancel the TV service. See ofcom.org.uk/phones-and-broadband/switching-provider/switching-broadband-provider "
If you use a bundle of services with a provider, for example home phone and broadband, you will usually follow the process shown in the above link. However, you may need to notify your old provider to cancel other services you are also switching as part of a bundle - particularly if the switch involves cancelling a TV service. Your old provider will give you information on what your options are regarding these services in the switching information they send to you
The article linked below which shows that daily the daily switch match success rate is currently hovering around 67% – 68%
/problems-remain-as-uk-broadband-isps-mark-first-year-of-one-touch-switching.html
The gaining provider (in this case VM) are responsible for the landline and broadband switch and should be able to see what went wrong. VM should either re-send the "switch complete" message or trigger a manual disconnection with EE.