I have had my BTC since 2014 & am thinking about selling some in case the market goes much lower. I am in the UK & bought through the company Quickbitcoin. I would also like to sell through them but they're not answering my emails or messages.

If I have to sell through an exchange, which one would be best? I am very wary of exchanges - I know a lot have been hacked. Any advice would be greatly appreciated. (My BTC are currently offline in a paper wallet so I presume when I import them to a wallet it would need to be somewhere which will also accept my Bitcoin Cash & Bitcoin Gold coins too).