A little story for you, I go out to the Gas Station and put £5 on my mobile so I can buy £5 worth of CE. I put the credit on my phone, I check my balance to make sure it went on properly, the robotic voiced lady confirms "5 pounds, exactly, of calling credit".
Next, I log into the Spiral Knights website, I go to My Account, then purchase energy, select the £5 option, type in my number and await a confirmation text. This is the interesting part. I receive a text telling me to reply "Y" to activate, so I do but then the computer tells me my phone doesn't have £5 on it so I check my balance. Low and behold I have £4.88 because I was charged for the text. Yeah, Spiral Knights just screwed me over, since I don't want to put £10 on my mobile so I can use £5 of it and they don't do £5.12 top ups I can no longer purchase CE.
Weldone Spiral Knights team, that was a really good f***ing job you've done there.
Bad news, genius: that's PayMo's doing, it's standard procedure for the payment method, and it's on the website. From the text on the purchase screen: "Charges will be made on your mobile bill or deducted from your prepaid account. Standard network charges may apply." It's not Three Rings' fault that you couldn't be arsed to read the third party site that you chose to use to pay for your CE. Cease kvetching. This is your own fault.