Banned IP Addresses In The Search Engines?

So we have an issue with one of the mainstream hosting companies we use, we just found out that they gave us a 'recycled' ip address from one of their old clients and it appears that this IP has been banned in Google.

Upon telling them about this they basically told us all we could do was purchase another ip address, is this common practice?

I figured that it would simply be a case of issuing us with another ip address to use and them simply trashing or re-issuing this banned ip to someone else who didnt know much about SEO.

Have you ever encountered this problem and if so, did you just buy a new ip or fight until they re-issued you an ip that wasnt banned because it wasnt actually your fault the recycled ip got banned to begin with?

Regards,

Lee