There is never any guarantee that the person you wish to speak to who has passed back home to the Spirit World will make a connection - we can't conjure them up - we just ask if they are available. Never be disappointed if this happens as it doesn't mean there is anything wrong with your loved one or that they don't wish to contact you. There can be various reasons why sometimes the process doesn't work satisfactorily. Perhaps conditions, such as the setting, the way you or the medium may be feeling - as in life people are drawn to those they feel comfortable or have an affinity with - so why would it not be the same between the two worlds The overall consideration is the clients well being and sometimes our loved ones know more than we do how you will be effected and will wait until you are ready. Mind you that said sometimes they can be very impatient and be ready and waiting before you arrive!
It is important that you feel comfortable and that proof is given in a way you can understand it - if you think the person giving the sitting is not working honestly you have the right to (politely of course) request the sitting be brought to a close. I personally do not see why if a client is not satisfied they should pay for the service provided, but that would be something that should be discussed prior to the start of the sitting with the person you made the appointment with. Most reputable workers in this field will be as disappointed as you may be and they would have prepared for the sitting prior to your attendance. They would usually have invested a great deal of money, time, emotional and personal upheavel in their traIning prior to working with the public, so perhaps an agreed token for their time may be of mutual satisfaction.
There are a great many mediums/clairvoyants/psychics who are extemely ethical and try to work to the best of their capability and word of mouth recommendation is often the best way of finding a reputable one. At the risk of curses, poisonous darts and other such mumbo jumbo being sent my way, if you are enouraged/frightened or coersed in anyway to hand over any money other than the fee that has been mutually agreed - get up and leave straightaway. Unfortunately as in all walks of life there are charlatans who prey on the vulnerable - and this work obviously deals with emotionally stressed and vulnerable, grieving people who can be at greater risk from being taken advantage of.
Remember when you are attending for your sitting, you are really making an appointment with the Spirit World, whether that be a personal loved one or the mediums Guides and Helpers, so to arrive on time or inform the medium if you are not able to keep the appointment is beneficial (and polite) to all concerned - yes, I know, I heard the joke too - you would think we would know you're not coming!
There is a presumption that our loved ones and the Spirit World know everything, but it doesn't hurt to ask prior to going for a private sitting or a demonstration that you silently in your mind ask that the person you wish to hear from will be there and make their presence known. The more relaxed and open minded you are will help the sitting, be aware not to give too much information unless asked to clarify something that is brought forward - a reputable worker is not there to be tested, I can assure you they will be as keen as yourself to give of their best, and any sitting whilst sometimes sad and emotional should also leave you feeling calmer, peaceful and uplifted.