No matter how much I spend, it's not coming out my bank UK?

I'm currently with Natwest and I have been since the age of 13. I have a normal debit card and I can't go below 0.00 so I can't really go into debit as it won't let me (thank god) but this is the question.

A week ago I ordered the iPhone 5S off apple store (so that's £549) YET after that I spent roughly around £14 on ebay and my balance is currently up to £556.85 and my availble money is at a number which I shall tell. But no matter how much I spend that available money is not declining. Although my ebay is linked to my ebay and paypal, I have funds in my paypal that are still coming through. So where exactly is my money coming from if my funds stay the same? It's been like that for a few days now. Even my mum has no idea she says just to trust the available money.

NOTE: Just for those who are trying to answer this question to troll, the available amount means what I can SPEND. The balance is what I have but can't spend IE what I already brought (the iPhone and stuff off ebay)

Nice question.
yes it makes sense to treat you balance accurately it also makes sense to spend wisely.

However, a buissnuis economic argument, would be, is it worth spending the mony wile its there
is the contract capable of sustaining that position and, what will be the final outcome.therefore returning to The worth of spent money.

make a list of things, if any make sense people you know, will offer you support.

Sometimes when you charge the card online in somewhere they don't charge you instant, they will charge like after a trial or something

Don't Forget To Smile.