I have a common goldfish and a Comet that I got for my 13th Birthday, ever since we have had them there has been problems

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We got them from 'pets at home' and we where told to keep an eye out for any white spots incase they got 'Ich', so when we noticed them we went straight to the shop and got some 'Ich' treatment. We gave it to them and they didn't move from the bottom of the tank for a whole day. So I went to check on them and noticed that they had lost their colour and their tails where covered in white spots and there fins and tails where in strands

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Whats wrong with them have they got 'Ich', 'Finrot' or what?
Please Help!