My old kitchen mixer tap was leaking so I purchased a new Mondella sink mixing cadenza on 15 February 2021 and fitted it to the sink. The spout swivel is very tight and I can not tighten the tap strongly enough so it soon works loose. what can I do? Do I need to get a stronger person to tighten the tap bellow the sink. Is there an adjustment to slightly loosen the spout so it rotates more freely? Is the unit faulty? It is not working as it should so should I return the tap and replace it with another new tap?