It's taxable income to you unless you have an amount of unreimbursed medical expenses to which you can apply the distribution.  If you are under age 65 at the time of the distribution, a taxable distribution is also subject to a 20% early-distribution penalty.

It's pretty bad form for the HSA custodian to treat these as distributions unless the custodian gives your the option to pay these fees directly yourself and only takes the money from the HSA if you fail to do so.  Either pay the fees directly or transfer the HSA to a different HSA custodian that has a better fee structure.