BlockChainPoolMining.com Review

I was told that if invested just $550 I would receive $7,500 within one week. I ask them how this is possible and they said it had to do with the high "Hash" rate of Bitcoin Mining presently. When my profit was about $5,500 I wanted to withdraw. They told me that I would need to pay 20% of my total balance UP FRONT to release my funds. (Like an idiot?) I paid them the "Withdrawal Fee". Then they said I should pay an extra $2,600 in Tax according to new 'IRS' laws. By this time my Wallet had grown to over $14,000. That's where I drew the line and did not pay them as I have not received any money from them but they keep asking for more. I still have that $14,000 available to me they have assured me but I would nee to pay that $2,600 Tax. Can ANYONE please help me and take me out of my misery and let me know whether I have been scammed or not?