CF7 Grid Extention Html disapears after saving

I want this to be as follows;

<div class="row">
  <div class="col-lg-6">
    <div class="form-group"><input type="text" name="date-delivery" placeholder="Teslim Edilecek Gün" data-timepicker="true" value="" class="wpcf7-form-control wpcf7-text wpcf7-validates-as-required js_datepicker-1 format24 form-control"><div class="form-group__icon icons-747310"></div></div>
  </div>
  <div class="col-lg-6">
    <div class="form-group"><input type="text" name="date-pick-up" placeholder="Teslim alınacak gün" value="" data-timepicker="true" class="wpcf7-form-control wpcf7-text wpcf7-validates-as-required form-control js_datepicker-2 format24 wpcf7-not-valid"><div class="form-group__icon icons-747310"></div></div>
  </div>
</div>

But every time I update it automatically reverts to this code

<div class="row">
  <div class="col-lg-6">
    <div class="form-group"><input type="text" data-timepicker="true" value="" class="wpcf7-form-control wpcf7-text wpcf7-validates-as-required js_datepicker-1 format24 form-control"><div class="form-group__icon icons-747310"></div></div>
  </div>
  <div class="col-lg-6">
    <div class="form-group"><input type="text" value="" data-timepicker="true" class="wpcf7-form-control wpcf7-text wpcf7-validates-as-required form-control js_datepicker-2 format24 wpcf7-not-valid"><div class="form-group__icon icons-747310"></div></div>
  </div>
</div>

How can i fix this