How can I get a refund if the heating is less than 18 degrees?

Indoor temperature 18 degrees, plus or minus 2 degrees is normal. If the temperature can't meet the standard, it needs to be appraised by a professional testing institution. If it fails to meet the standard, the fee will be refunded according to the actual number of days it fails to meet the standard. For the number of days when the indoor temperature does not reach the specified standard or agreed temperature during the heating period, the heating enterprise or the management unit of the heat exchange station shall refund the heating fee to the user according to the actual number of days confirmed by both parties, and bear the liability for breach of contract in accordance with the heating contract.