personal greeting stopping changeover?

[#1]

I am in the process of changing provider from Plusnet. I received a text from my new provider which reads "We have been unable to provide you a service at present due to a personal greeting on your line. Please may we ask you to contact your current supplier and ask for 1571PG to be removed."
Can anybody here help me out with this in any way?
Thanks

[#2]

You should be able to remove voicemail Here usually takes anywhere between a few minutes and 1 working day