Have you logged out completely and back in (exited the client and restarted it) since you got the membership? Sometimes I have to do that to gain full access to the member features. In my 7+ years of playing I have never heard of a transaction going through and not giving access to what you paid for, so i seriously doubt you will need to react in such an extreme way as to issue a chargeback.
You didn't give us that much information to work with. 1. You can always email support with questions and they will help you. 2. In order to access locations you must have completed the prior area. (ie you must complete Unicorn Way, Triton Avenue, Cyclops Lane, and FireCat Alley and defeat Lord Nightshade in order to go to Krokotopia. (You don't want to just jump into Zafaria anyway as the baddies would kill you in a second and it annoys the other players who are the appropriate level). 3. Talk to Ambrose/Follow the main storyline that should get you on track. 4. Your membership appears to be working or you wouldn't have been able to post on the boards. 5. If you are really determined you can port to friends, but again it is recommended that you follow the storyline as that is how you gain access to new worlds.
Having a membership doesn't allow you access to all areas. It allows you access to all areas that are unlocked by your questing level, and you can port into other areas if you have a friend there. How exactly is it blocking you? If it's showing you the Crown purchase screen for the area then you need to contact customer support because it's not registering you as a member. If you just mean that you can't go wherever you want through the spiral gate, it's working as intended.
You realize you do have to actually quest to move onto new places, right? Membership just allows you to use those places. Also, if I'm correct, you can't get a refund on your membership.
That happened to me yesterday when I was trying to level up my pets with the bonus. I noticed I wasn't getting any extra xp, so I tested it out by porting to Krok, and it said I had to pay for the zone, even though I've been a member for months now. And when it comes the time for my membership to renew, it always automatically did it. But suddenly it just stopped. I ended up actually having to repurchase my membership. I'm not sure why it happened, it really stressed me out.
That happened to me yesterday when I was trying to level up my pets with the bonus. I noticed I wasn't getting any extra xp, so I tested it out by porting to Krok, and it said I had to pay for the zone, even though I've been a member for months now. And when it comes the time for my membership to renew, it always automatically did it. But suddenly it just stopped. I ended up actually having to repurchase my membership. I'm not sure why it happened, it really stressed me out.
It's possible that the card originally used expired. Renewals use the data you gave at time of purchase, so even if you got a new card with the same number, if the expiration date doesn't match it won't automatically renew.