This suggests to me that the disappearance of Virgin and Boost refills from CallingMart.com was commercial dispute of some sort between the two companies rather than a general ban by Sprint on online refill sales by third parties as CallingMart originally claimed.
I just saw this on CallingMart's Facebook page;
"Dear Customers, We are no longer able to resell Boost or Virgin Refills online as it is now prohibited from online reselling per the carrier, and it's only a matter of time for it to be removed from other online stores as well, if not removed already.
We are very sorry about that - it's also a big hit for us but it's really out of our hands. On the other hand we are preparing to resell to a very strong alternative, which is based on the same network, and have very competitive plans to Boost and Virgin: www.MingoWireless.com.
We will be offering great discounts as well on top of the already nice plans they have (which we were not able to do with Boost and Virgin before). We really appreciate your business and we hope we will be able to keep you as our customers through our alternative options."
It looks like the only ways to top up a Boost or Virgin Mobile account going forward are by buying top-up cards at supermarkets, chain drugstores and big box retailers like Target or by using a credit or debit card at boostmobile.com or virginmobileusa.com
I will miss using Callingmart which was convenient and sold Boost and Virgin refills at a discount. I really don't like using virginmobileusa.com as they charge sales tax on refills even here in California, where prepaid topups are classified as a service and are not subject to sales tax. I wonder if the state even gets the sales tax that Virgin is collecting on these non-taxable items?
This seems like a very strange move by Sprint, which is Boost and Virgin's parent company. Most business want to make it easier for customers to buy their products by making them available through as many channels as possible.
The only possible explanation I can think of for the ban on online sales is that Sprint wants to drive online sales to their sites to avoid paying sales commissions. But that doesn't explain why physical stores are still allowed to sell refills, and earn commissions. When you consider the cost of manufacturing and shipping top-up cards, you would think Sprint would want to encourage any kind of online sales.
If you are looking for a deal on Boost and Virgin top-up cards, Target (stores only, not online) is having a 5% sale on all prepaid wireless top-up cards, this week only. You can save an additional 5% by using a Target "RED Card".