code: public void billingAccount_DELETE(String billingAccount, String details, OvhTerminationReasonEnum reason) throws IOException {
  		String qPath = "/telephony/{billingAccount}";
  		StringBuilder sb = path(qPath, billingAccount);
  		query(sb, "details", details);
  		query(sb, "reason", reason);
  		exec(qPath, "DELETE", sb.toString(), null);
  	}
docs: Ask for a billing account termination.
  
  REST: DELETE /telephony/{billingAccount}
  @param details [required] Termination reason details
  @param reason [required] Termination reason
  @param billingAccount [required] The name of your billingAccount