It's the scammer, stay away
Yes you should stay away from confirmtx when it comes to paying them. They aren't really accelerating your transaction and if you sent the payment they are asking it's more of a donation to them already. I have used them before and I can say that I'm very disappointed that they don't know how to reevaluate transactions that has low and high fee.
They received money but don't do anything
I checked my current payment today. They changed their wallet address, so my current status of payment changed into "Pending: This acceleration fee is not paid yet."
=> That's the proof that
http://confirmtx.com is totally FAKE-PAGE, which created for SCAM
Somebody should stop their site, so nobody can get this SCAM