I sent through some bitcoins to them and the transaction has been confirmed on blockchain a lot of times but they didnt transfer the bitcoin to Hashflare.io .
If your transaction is confirmed on blockchain than it will be hashflare responsibility to make your deposit appear on your account if you have sent bitcoin to correct deposit address.
Focus on contacting hashflare support rather than cryptopay and also don't forget to check the deposit address is correct or not.
cryptopay handles the bitcoin deposits to hashflare.io so if there is a problem on deposit it must be a fault on cryptopay's side so contacting support of cryptopay is needed and not hashflare though in some cases that cryptopay already forwarded the "paid" message to hashflare and still hasn't given you the power you bought it is on hashflare's side