They can just take money out from your existing cr...

They can just take money out from your existing credit without giving any reason. I topped up 10 pounds (plus existing 3 pounds in the balance) and without making any phone call, all credit is gone. I topped up 12.5 pounds for a 3gb data bundle and just used less than 500 mb (checked on my phone) and they claimed that I have used up all 3gb and stopped my bundle. When I called the customer service (they charged for this) and asked for a reason, the guy just hung up on me. I gave a 0 rating to the service straight away after the call just now (~16:35 22Jul16). They don't even deserve a 0 rating and I will never use this company again. I selected one star because this is the lowest I can select.