Do they always do that as soon as somebody wins big money or something?!
At least if you start winning consistently, pretty standard practice for bookies to only keep 'customers' who are paying them in the short and long term. Helps boost profits if you only keep the suckers with their 6+ accumulators and crazy bets.
Got kicked out of BlueSq when I was at uni, they told me that they had noticed "suspicious activity on my account" - i.e. four big wins in a four-week period
PS: Dinho lad, you'll be safe for a while yet - just make sure you withdraw your winnings immediately when you finally land the jackpot