You can make numerous transactions with no problem, then suddenly they'll block your card, even though there's never been an issue to be a reason to block you out.
They apparently don't want long time, repeat customers, but rely on only new buyers.
If that's what they want, then so be it. Same typical issue with all these businesses like this. No communication. They cancel without communicating why or what the problem is so it can be resolved. Assuming there even is one in the first place. Or their websites are glitchy garbage. I can point out a recurring theme with all of them & it's you getting charged on one screen, before the purchase is approved on their site. Often sticking you with the charge at your bank or card for sometimes 5-12 days, for it to fall off.
You ought've decided if you will sell the card, before the person is charged & if their payment goes through, then it should not be canceled immediately at this point when they'ved paid. VERY, VERY DISAPPOINTING. I was actually interested in increasing my purchases, BEFORE they suddenly decided to give me crap checking out "OUT OF THE BLUE!"