Have you paid of the service or Claimed a freebie ?
If its a freebie claimed, there is nothing much you can do other than writing a Honest Review.
If you have paid, contact the Seller, ask him the code and get things done. Always go through the rules and regulations of the Marketplace before buying or selling things. Now a days, having 2 way verification is quiet common, it asks you to verify by sending a code to your phone even if you clean your browser and then login. what do you expect changing a location will do ? If the seller is a genuine guy, and you surely paid for the service, he will help you out, if not Read the Rules of the Marketplace( i Hope you did read everything before buying, its the Green threads in all sections with Do's and Don't) and contact the right authorized person for advice.
Enjoy being here, Where nothing is spoon-feeded yet everything is directed