Identify the unfair aspect with respect to the sentence extracted from an online Terms of Service:
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you acknowledge and agree that headspace is authorized to charge the payment method used for ( i ) the initial annual or two year subscription fee at the rate secured at the time of purchase , and ( ii ) the renewal subscription fee ( s ) at the non-discounted rate in effect at the time of any such renewal . 

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. OPTIONS: ['Unilateral termination' 'Limitation of liability' 'None'
 'Contract by using' 'Arbitration' 'Content removal' 'Jurisdiction'
 'Choice of law' 'Unilateral change'].