My apologies Songrit
You should have only been billed once per month however it appears you were billed twice (it says you have one last payment to be made next month). However I am talking with Sam Cart about their mix up, so I will keep you updated.
My apologies for the inconvenience - right now it looks like you've paid a total of 3 of the 4 payments because of this so you have one more in March.But I will still try to get Sam Cart to try to reverse this and sort things out, I will keep you updated. Thanks for your patience, this is very frustrating that this happened, apparently it happened to a lot of their customers this week so they're trying to sort it all out now.
Let me know if you have any questions, happy to put your mind at ease
Thanks Songrit!