This is a tricky situation as if you signed up to pay a specified amount to VF for a specific period of time, you are under contract to pay that amount regardless of a change of circumstances. I would advise sending them an email telling them that because of your change in circumstances, the contract between you and VF has been "frustrated" and is unable to be completed. Frustration is an English common law term which acts as a device to set aside contracts where an unforseen event either renders contractual obligations impossible, or radically changes the party's principal purpose for entering into the contract. This seems to be the best possible option in your siituation though I would remind you that they are under no obligation to accept this argument. If you wish to take it further should they reject this position, then you will have to go to court.
Hope this helps